{
"generated": "2026-10-16T20:26:28Z",
"content_changed": "2026-10-16T20:14:42Z",
"licence": "Quote freely with attribution and a link to waterfilterhouse.com (the url of the product or the guide). Prices are in euro including VAT and hold at the moment of the build; order directly on the product page. No medical advice. waterfilterhouse.com is a shop of Alternatievemiddelen.nl B.V. (Hegelsom, the Netherlands).",
"count": 26,
"guides": [
{
"title": "BOROUX water filter: Legacy and Legacy Compact, elements and accessories at a glance",
"titles": {
"en": "BOROUX water filter: Legacy and Legacy Compact, elements and accessories at a glance",
"de": "BOROUX Wasserfilter: Legacy und Legacy Compact, Elemente und Zubehör im Überblick",
"nl": "BOROUX waterfilter: Legacy en Legacy Compact, elementen en accessoires op een rij"
},
"kicker": "Brand · BOROUX water filters",
"urls": {
"en": "https://waterfilterhouse.com/en/brand/boroux/",
"de": "https://waterfilterhouse.com/de/marke/boroux/",
"nl": "https://waterfilterhouse.com/nl/merk/boroux/"
},
"url": "https://waterfilterhouse.com/en/brand/boroux/",
"intro": "The Legacy and the Legacy Compact in stainless steel, white, black and sage green side by side, with the Foundation Black elements, the ProActive fluoride filters and everything that goes with them. From the only BOROUX dealer in Europe, with today's stock.",
"body_markdown": "## What is BOROUX?\n\nBOROUX makes gravity filters from food-safe stainless steel (AISI 304): two chambers stacked on top of each other, the water sinks through the filter elements in the upper chamber and is ready, filtered, behind the tap. No power, no connection to the water mains, no installer.\n\nThe brand was set up by the team behind the largest American Berkey dealer, together with the factory that made the original Black Berkey formula. You can read the whole story in [BOROUX: the successor to Berkey](/uitleg/boroux-waterfilter/). Alternatievemiddelen.nl in Hegelsom is the only official BOROUX dealer in Europe.\n\n## Two sizes, four colours\n\nThe **Legacy Compact** (6.8 litres) fits in most kitchens and, according to the shop, is suitable for 1 to 3 people. The **Legacy** (11.4 litres) is made for 2 to 6 people and can be expanded from two to four elements. Both come as standard with two BOROUX Foundation Black elements, and both are available in stainless steel, white, black and sage green, with matching taps and sight glass taps. A water filter you do not have to hide away.\n\n## The Foundation Black elements\n\nThe **BOROUX Foundation Black** elements use the same basic formula of, among other things, compressed activated carbon as the original Black Berkey elements, made in the same place in America, with new patented improvements. They have been tested by the independent IAPMO laboratory and certified by WQA to NSF/ANSI 42 (taste, odour, particulates), NSF/ANSI 372 (lead-free material) and NSF/ANSI 401 (microplastics). They also fit in any Berkey system.\n\nGuideline for Dutch tap water and average use: replace after a maximum of three years. That is a practical guideline, not a fixed period; more on this in [how often do you replace a filter element?](/uitleg/filterelement-vervangen/)\n\n## Fluoride: the ProActive add-on filters\n\nThe Foundation elements do not filter fluoride, and BOROUX says so plainly. If you want to reduce fluoride, fit the **ProActive Fluoride** filters underneath: one per Foundation element, with an upflow design that guides the water from the bottom to the top, and without aluminium oxide. They also fit under Black Berkey elements. Guideline: replace after a maximum of one year.\n\n## Priming\n\nFoundation elements are primed before first use: you saturate them with water so that the water flows through them properly. With BOROUX's electric priming pump this takes about ninety seconds per element. Would rather not do it yourself? With the Prime Service, the shop primes them for you.\n\n## More than a water filter\n\nBOROUX also makes glass drinking bottles, a glass serving jug, stainless steel drinking cups, a wooden stand, a shower filter and a maintenance kit for filter and system. You will find them all on this page.\n\n> **In short.** BOROUX is the continuation of the original Black Berkey formula, by the people who made and sold it. Two stainless steel systems (6.8 and 11.4 litres) in four colours, Foundation Black elements that also fit in a Berkey, fluoride with the ProActive add-on filters, and in Europe only for sale at Alternatievemiddelen.nl.\n\n## Frequently asked questions\n\n### Which BOROUX suits me?\n\nAccording to the shop, the Legacy Compact (6.8 litres) is suitable for 1 to 3 people, the Legacy (11.4 litres) for 2 to 6. If you cook a lot with filtered water or prefer not to top up often, choose the larger one. The [selection guide](/keuzehulp/) works it out with you.\n\n### Where do you buy BOROUX in the Netherlands and Europe?\n\nOnly at Alternatievemiddelen.nl in Hegelsom: the only official BOROUX dealer in Europe. Tom and Melanie simply answer questions via WhatsApp.\n\n### Is BOROUX the same as Berkey?\n\nNo. BOROUX is a brand of its own, set up by the team behind the largest American Berkey dealer together with the factory that made the Black Berkey formula. The Foundation Black elements do fit in a Berkey. The difference from the Black Berkey lies in the registration: BOROUX makes no claims about bacteria and viruses. More in [Black Berkey alternative](/uitleg/black-berkey-alternatief/).\n\n### Do BOROUX Foundation elements fit in my Berkey?\n\nYes. The Foundation Black elements fit in any Berkey system, and the ProActive fluoride filters also fit under Black Berkey elements.\n\n### Does a BOROUX filter fluoride?\n\nThe Foundation Black elements do not. For that there are the ProActive Fluoride add-on filters: one under each Foundation element.\n\n### How long do the elements last?\n\nAs a practical guideline for Dutch tap water and average use: Foundation Black a maximum of three years, ProActive fluoride filters a maximum of one year. If the upper chamber starts to empty noticeably more slowly or the taste changes, it is time sooner.\n\n### Do you have to prime BOROUX elements?\n\nYes, before first use. With the electric priming pump this takes about ninety seconds per element, or you can let the shop do it with the Prime Service.",
"product_ids": [],
"brand": "BOROUX",
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:43:45Z"
},
{
"title": "Berkey water filter: all models, sizes and parts at a glance",
"titles": {
"en": "Berkey water filter: all models, sizes and parts at a glance",
"de": "Berkey Wasserfilter: alle Modelle, Größen und Teile im Überblick",
"nl": "Berkey waterfilter: alle modellen, maten en onderdelen op een rij"
},
"kicker": "Brand · Berkey water filters",
"urls": {
"en": "https://waterfilterhouse.com/en/brand/berkey/",
"de": "https://waterfilterhouse.com/de/marke/berkey/",
"nl": "https://waterfilterhouse.com/nl/merk/berkey/"
},
"url": "https://waterfilterhouse.com/en/brand/berkey/",
"intro": "Travel, Big, Royal, Imperial and Crown side by side: capacity, size and flow rate per model, plus the elements, fluoride filters and parts, with today's stock.",
"body_markdown": "## What is a Berkey?\n\nA Berkey is a gravity filter: two stainless steel chambers stacked on top of each other. You pour tap water into the upper chamber, gravity pushes it through the filter elements, and the filtered water is ready in the lower chamber behind a tap. No power, no connection to the water mains, no installer. The chambers are made of polished stainless steel (AISI 304) and last for decades; it is the elements that you replace. For exactly how this principle works, see [how does a gravity filter work](/uitleg/hoe-werkt-een-zwaartekrachtfilter/).\n\nThe brand comes from the United States; the brand owner is New Millennium Concepts. All models work in the same way. What differs is the capacity of the chambers and how many elements fit inside.\n\n## Which size suits you?\n\nThe table above gives the shop's guideline for each model in number of people. A handy rule of thumb: allow roughly two litres of chamber capacity per person as a daily buffer. If you are torn between two sizes, choose the larger one: you will have to top up a larger upper chamber less often, and the larger models hold more elements, so the water flows through faster.\n\nThe **Travel Berkey** is the compact choice for a small household, and also fits in a camper or holiday home. The **Big Berkey** is the classic for home. The **Royal Berkey** gives a larger family room to breathe, and the **Imperial** and **Crown** are for large households, an office or a group. For on the go there are the **Go Berkey** and the **Sport Berkey** drinking bottle with filter.\n\n## What about the Black Berkey elements?\n\nIn early 2023, the US environmental agency EPA ruled that the Black Berkey elements fall under the American pesticides act: the elements contain silver, and claims had been made about bacteria and viruses. Since then, individual elements have no longer been supplied. Alternatievemiddelen.nl still sells the systems themselves with two original Black Berkey elements inside, from the remaining stock. The expectation is that Berkey will supply them with Phoenix Gravity New Millennium Edition elements as standard in future.\n\nFor replacement there are three successors that fit in the same housing:\n\n- **BOROUX Foundation Black**: the same basic formula as the Black Berkey, made by the team behind the largest American Berkey dealer together with the factory that made the original formula. Guideline: a maximum of three years per set.\n- **Phoenix Gravity New Millennium Edition**: made on behalf of New Millennium Concepts, the brand owner of Berkey. Friendly price; guideline a maximum of one year.\n- **Coldstream FTO PLUS**: ceramic, no priming needed and it also filters fluoride. Guideline a maximum of six months.\n\nThe guidelines apply to Dutch tap water and average use; they are not fixed periods. You can read the whole story in [Black Berkey alternative](/uitleg/black-berkey-alternatief/).\n\n## Fluoride and arsenic\n\nThe black elements (Black Berkey and BOROUX Foundation) do not filter fluoride. If you want that, you screw add-on filters underneath: the original **Berkey PF-2** fluoride and arsenic filters, or the **BOROUX ProActive** fluoride filters. These work with an upflow design and also fit directly under Black Berkey elements. You use one add-on filter per black element and replace them after a maximum of one year.\n\n## Priming, cleaning and replacing\n\nBlack elements are primed before first use: you saturate them with water so that the water flows through them properly. You can do this with a primer, with BOROUX's electric priming pump, or you can let the shop do it with the Prime Service. If the upper chamber starts to empty noticeably more slowly after a while, priming again or a clean will help. More on this: [cleaning and maintaining a water filter](/uitleg/waterfilter-onderhoud/) and [how often do you replace a filter element?](/uitleg/filterelement-vervangen/)\n\n> **In short.** A Berkey is a stainless steel gravity filter without a connection, in sizes from compact to very large. The systems are still for sale with original Black Berkey elements; for replacement, BOROUX Foundation, Phoenix Gravity and Coldstream FTO PLUS fit in the same housing. You filter fluoride with an add-on filter under each black element.\n\n## Frequently asked questions\n\n### Is Berkey still for sale in the Netherlands?\n\nYes. Alternatievemiddelen.nl sells the Berkey systems with two original Black Berkey elements inside, while stocks last. You can see what is in stock today under the models on this page. Individual Black Berkey elements are no longer available; for those there are the successors.\n\n### Which Berkey suits a family of four?\n\nAccording to the shop, the Big Berkey is suitable for 1 to 4 people, the Royal Berkey for 2 to 6. With four people you are at the upper limit of the Big. If you cook a lot with filtered water or prefer not to top up often, choose the Royal.\n\n### Does a Berkey have to be connected to the water mains?\n\nNo. A Berkey works on gravity: you fill the upper chamber by hand. No power, no connection, no installation.\n\n### Do BOROUX Foundation elements fit in a Berkey?\n\nYes. The BOROUX Foundation Black elements fit in any Berkey system, as do the Phoenix Gravity elements and the ceramic Coldstream FTO PLUS. If you are unsure about your system, the [selection guide](/keuzehulp/) points out the right element for each brand.\n\n### How long do the elements last?\n\nThat depends on your water and your consumption. As a practical guideline for Dutch tap water and average use, Alternatievemiddelen.nl advises: Black Berkey and BOROUX Foundation a maximum of three years, Phoenix Gravity a maximum of one year, Coldstream FTO PLUS a maximum of six months. If the chamber starts to empty noticeably more slowly or the taste changes, it is time sooner.\n\n### What is the difference between Berkey and BOROUX?\n\nBOROUX is a brand of its own, set up by the team behind the largest American Berkey dealer together with the factory that made the Black Berkey formula. The BOROUX Foundation elements fit in a Berkey; in addition, BOROUX makes its own stainless steel systems (Legacy and Legacy Compact), also in white, black and sage green. Alternatievemiddelen.nl is the only BOROUX dealer in Europe. More in [the BOROUX story](/uitleg/boroux-waterfilter/).\n\n### Where can I find parts for my Berkey?\n\nOn this page, under parts and accessories: stainless steel taps and taps with a sight glass, stands per model, rubber rims, wing nuts, rings, blocking plugs and primers. You order through the online shop.",
"product_ids": [
81536
],
"brand": "Berkey",
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:43:45Z"
},
{
"title": "Pure Filters water filter: Voyager, Home and Family with Coldstream FTO PLUS at a glance",
"titles": {
"en": "Pure Filters water filter: Voyager, Home and Family with Coldstream FTO PLUS at a glance",
"de": "Pure Filters Wasserfilter: Voyager, Home und Family mit Coldstream FTO PLUS im Überblick",
"nl": "Pure Filters waterfilter: Voyager, Home en Family met Coldstream FTO PLUS op een rij"
},
"kicker": "Brand · Pure Filters water filters",
"urls": {
"en": "https://waterfilterhouse.com/en/brand/pure-filters/",
"de": "https://waterfilterhouse.com/de/marke/pure-filters/",
"nl": "https://waterfilterhouse.com/nl/merk/pure-filters/"
},
"url": "https://waterfilterhouse.com/en/brand/pure-filters/",
"intro": "The Voyager, Home and Family side by side: stainless steel gravity filters with ceramic Coldstream FTO PLUS elements, with no priming and with fluoride reduction included. With capacity, size, price and today's stock.",
"body_markdown": "## What is Pure Filters?\n\nPure Filters makes gravity filters from stainless steel (AISI 304) that come as standard with two **Coldstream FTO PLUS** elements. The principle is that of any gravity filter: tap water goes into the upper chamber, sinks through the elements, and the filtered water is ready in the lower chamber behind a tap. No power, no connection to the water mains. For how that works, see [how does a gravity filter work](/uitleg/hoe-werkt-een-zwaartekrachtfilter/).\n\n## The element makes the difference\n\nThe Coldstream FTO PLUS is a ceramic element with a carbon core, from the English factory that also made the ProOne G2.0 elements. This makes it low-maintenance: **priming is not necessary**, and fluoride reduction is already built in, so separate add-on filters are not needed either. According to the shop's product information, the element is NSF certified to NSF/ANSI 42 and tested to NSF/ANSI 42, 53 and P231.\n\nYou replace it after 1,500 litres or six months, whichever comes first. The element also fits Berkey, BOROUX, British Berkefeld and ProOne. The story behind it: [ProOne disappeared: the real element is called Coldstream FTO PLUS](/uitleg/proone-alternatief-coldstream/).\n\n## Three sizes\n\nAccording to the shop, the **Voyager** (6 litres) is suitable for 1 to 2 people, the **Home** (9 litres) for 1 to 4 and the **Family** (12 litres) for 2 to 6. A handy rule of thumb: allow roughly two litres of chamber capacity per person as a daily buffer. If you are unsure, choose the larger size: you will have to top it up less often.\n\n## Convenience versus service life\n\nAn honest comparison: Pure Filters wins on convenience and entry price. No priming, no add-on filters, and replacement is always the same element. On the other hand, you change the elements more often than the black elements from BOROUX or Berkey, for which a guideline of a maximum of three years applies. So count on the cost of elements per year, not just the purchase price. More in [which water filter should you buy?](/uitleg/welk-waterfilter-kopen/)\n\n## Maintenance\n\nClean once a month, together with the chambers: rinse the elements under a cold tap and lightly scour them with a scouring sponge. More on this: [cleaning and maintaining a water filter](/uitleg/waterfilter-onderhoud/).\n\n> **In short.** Pure Filters is the stainless steel gravity filter for anyone who wants it as simple as possible: three sizes (6, 9 and 12 litres), with Coldstream FTO PLUS elements as standard, with no priming and with fluoride reduction included. You change the elements every six months or after 1,500 litres.\n\n## Frequently asked questions\n\n### Do you have to prime Pure Filters elements?\n\nNo. The ceramic Coldstream FTO PLUS elements do not need to be primed: fit them, fill the upper chamber, done.\n\n### Does Pure Filters filter fluoride?\n\nYes. Fluoride reduction is built into the Coldstream FTO PLUS element itself; a separate add-on filter is not needed.\n\n### How often do you replace the elements?\n\nAfter 1,500 litres or six months, whichever comes first. If the upper chamber starts to empty noticeably more slowly sooner than that, clean the elements first.\n\n### Which Pure Filters suits me?\n\nAccording to the shop: Voyager (6 litres) for 1 to 2 people, Home (9 litres) for 1 to 4, Family (12 litres) for 2 to 6. The [selection guide](/keuzehulp/) works it out with you.\n\n### Do Coldstream FTO PLUS elements fit in my ProOne or Berkey?\n\nYes. The Coldstream FTO PLUS is the direct successor in the ProOne Traveler+, Big+ and Big II, and also fits Berkey, BOROUX and British Berkefeld. The [selection guide](/keuzehulp/) shows which element fits your system, per brand.\n\n### What is the difference from Berkey and BOROUX?\n\nBerkey and BOROUX work with black carbon elements that you prime and that last up to three years; for fluoride you fit an add-on filter underneath. Pure Filters works with the ceramic Coldstream element: no priming, fluoride included, change every six months. See also the [Berkey models](/berkey/) and the [BOROUX models](/boroux/).",
"product_ids": [
81536
],
"brand": "Pure Filters",
"created": "2026-10-16T08:42:19Z",
"updated": "2026-10-16T10:46:10Z"
},
{
"title": "Black Berkey alternative: what fits in your Berkey",
"titles": {
"en": "Black Berkey alternative: what fits in your Berkey",
"de": "Black Berkey Alternative: Das passt in Ihren Berkey",
"nl": "Black Berkey alternatief: dit past er in jouw Berkey"
},
"kicker": "Guide · black berkey alternative",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/black-berkey-alternatief/",
"de": "https://waterfilterhouse.com/de/ratgeber/black-berkey-alternatief/",
"nl": "https://waterfilterhouse.com/nl/uitleg/black-berkey-alternatief/"
},
"url": "https://waterfilterhouse.com/en/guides/black-berkey-alternatief/",
"intro": "Original Black Berkey filter elements are no longer being manufactured. Three successors fit the same housing, with BOROUX Foundation filters the most popular choice. The story behind it and the options available now.",
"body_markdown": "## Why the original Black Berkey filter elements disappeared\n\nIn early 2023, the American environmental agency EPA ruled that the Black Berkey elements fall under the American pesticide law: the filters contain silver (registered in the US as a pesticide) and claims were made about combating bacteria and viruses. The result: production of replacement elements has been at a standstill ever since, while Berkey's lawsuit against the EPA is still ongoing. New complete Berkey systems are still supplied with original elements from the remaining stock, but separate replacements are no longer available. And the stainless steel housings in particular are indestructible, so what fits in them?\n\n## Three successors, same housing\n\n**The BOROUX Foundation filter** is the most popular alternative, made by the team behind the largest American Berkey dealer together with the factory that made the original Black Berkey formula. Same basic formula, same place of production, new patented improvements, and on paper a different product: it no longer makes any micro-organism claims, which means the element falls neatly within the EPA rules. With average use a set lasts about three years (based on Dutch tap water and average use. **Please note!** This is therefore a practical guideline and not a fixed replacement period). [Read the whole BOROUX story](/uitleg/boroux-waterfilter/).\n\n**The Phoenix Gravity New Millennium Edition filter** is made on behalf of New Millennium Concepts, the brand owner of Berkey itself. Slightly smaller than the original, made in India, with a replacement cycle of about a year. More recently on the market, so with less long-term experience than the BOROUX variant.\n\n**The Coldstream FTO PLUS filter** is the different kind of option: ceramic, no priming needed and fluoride reduction included, from the English factory that also made the ProOne G2.0 elements. If you want to get away from black carbon elements, this lets you switch in one go.\n\nIf you want to keep fluoride and arsenic reduction with the black elements: the original PF-2 add-on filters are still available, and the new BOROUX Proactive supplementary filters also fit directly onto Black Berkey and BOROUX Foundation filter elements.\n\n## Which one do you choose?\n\nCount on lifespan, not on purchase price. The BOROUX Foundation costs more per element but lasts many times longer; the Phoenix is kindly priced to get started with; the Coldstream wins on convenience. All three provide their performance figures per substance in test reports, and that is exactly what you want to choose on.",
"product_ids": [
81461,
81483,
81536,
81377,
81467,
81468
],
"brand": null,
"created": "2026-10-16T08:42:16Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "PFAS in tap water: the facts, standards and developments",
"titles": {
"en": "PFAS in tap water: the facts, standards and developments",
"de": "PFAS im Leitungswasser: Fakten, Normen und Entwicklungen",
"nl": "PFAS in kraanwater: de feiten, normen en ontwikkelingen"
},
"kicker": "Facts · drinking water · updated July 2026",
"urls": {
"en": "https://waterfilterhouse.com/en/pfas/",
"de": "https://waterfilterhouse.com/de/pfas/",
"nl": "https://waterfilterhouse.com/nl/pfas/"
},
"url": "https://waterfilterhouse.com/en/pfas/",
"intro": "Small amounts of PFAS can occur in Dutch tap water. Dutch drinking water meets the statutory standard and, according to the RIVM, can simply be drunk. At the same time, the RIVM advises reducing exposure to PFAS further wherever possible. On this page we keep track of the key facts, standards and developments concerning PFAS in Dutch drinking water.",
"body_markdown": "## What is the current situation with PFAS in Dutch tap water?\n\nPFAS stands for **per- and polyfluoroalkyl substances**. It is a collective name for thousands of chemicals that break down with great difficulty and can therefore remain in the environment for a very long time.\n\nPFAS can end up in sources of drinking water via soil, surface water and groundwater, among other routes.\n\nAccording to the RIVM, small amounts of PFAS can occur in Dutch drinking water. The amount varies depending, among other things, on the source from which the drinking water is made. Drinking water from groundwater contains on average less PFAS than drinking water produced from surface water.\n\nFor drinking water alone, average exposure to PFAS is below the health-based limit value. On average, people in the Netherlands take in more PFAS through food than through drinking water.\n\nAccording to the RIVM, Dutch tap water can therefore simply be drunk.\n\n## Which standards apply to PFAS in drinking water?\n\nSince 2026, a statutory standard of **100 nanograms per litre (ng/L) for the sum of twenty PFAS** has applied.\n\nIn addition, the RIVM advises a health-based guideline value of:\n\n**4.4 ng/L expressed in PFOA equivalents (PEQ)**.\n\nThese two values cannot be compared directly with each other.\n\nThe statutory standard looks at the sum of twenty PFAS. The health-based guideline value converts various PFAS into PFOA equivalents on the basis of their relative potency.\n\nIt is therefore not correct to simply state that 4.4 ng/L is a version of the statutory standard of 100 ng/L that is more than twenty times stricter. The calculation methods differ.\n\n## The development of PFAS in Dutch drinking water\n\n### October 2022: RIVM recommends lower concentrations\n\nThe RIVM advises reducing the amount of PFAS in drinking water made from river water even further.\n\nIn more than half of the measurements examined for drinking water from river water, the concentration is above the health-based guideline value. At the same time, the RIVM stresses that drinking tap water remains safe.
\n\n### July 2025: national blood study on PFAS\n\nThe RIVM publishes the results of a national blood study. In almost all the people studied in the Netherlands, several PFAS are found in the blood.\n\nExposure to PFAS does not come only from drinking water. On average, food makes a considerably larger contribution.
\n\n### January 2026: European drinking water standard comes into force\n\nFrom 2026, a statutory drinking water standard of a maximum of 100 ng/L applies to the sum of twenty PFAS.\n\nDutch drinking water meets this statutory standard.\n\nIn addition, the RIVM advises using the health-based guideline value of **4.4 ng/L PEQ** to assess the presence of PFAS in drinking water.
\n\n### April 2026: discussion about PFAS and home filters\n\nRadar looks at PFAS in tap water and the use of water filters at home.\n\nExperts from the RIVM and KWR state that an additional water filter is not necessary in order to drink Dutch tap water safely. They also point out how important it is to maintain filters properly.\n\nAt the same time, various filter technologies can demonstrably reduce PFAS. The relevant question is therefore not only whether a filter can reduce PFAS, but above all **which PFAS have been tested, how much is reduced and up to what filter capacity that performance has been demonstrated**.
\n\n### June 2026: PFAS will remain a point of concern for decades\n\nIn an exploratory modelling study, the RIVM investigates how PFAS concentrations in the Rhine and Meuse may develop if PFAS emissions are strongly restricted.\n\nAccording to these calculations, even with far-reaching European restrictions it could still take roughly **thirty years** before additional treatment for the PFAS studied is no longer needed.\n\nThis underlines how important it is to prevent PFAS from ending up in the environment and in our drinking water sources.\n\n## Can you filter PFAS out of tap water?\n\nActivated carbon, ion exchange and reverse osmosis, among other methods, are used for this.\n\nHow effective a water filter is depends, among other things, on the filter material used, the specific PFAS and the amount of water that has already passed through the filter. The presence of activated carbon alone is therefore not enough to determine how well a filter reduces PFAS.\n\nIf you want to filter PFAS out of tap water, you are well advised to look at independent laboratory tests of the complete filter.\n\n[Read our in-depth study: filtering PFAS out of tap water, what really works?](/uitleg/pfas-uit-kraanwater-filteren/)\n\n## Do you need to filter Dutch tap water because of PFAS?\n\n**No. An additional water filter is not necessary in order to drink Dutch tap water safely.**\n\nAccording to the RIVM, Dutch tap water can simply be drunk.\n\nIf you want to limit your personal exposure to PFAS via drinking water further, you can choose to filter your tap water additionally.\n\nThat is a personal choice.\n\nIf you do choose to, don't look only at claims such as '*filters PFAS*'. Check whether the complete filter has been independently tested, which PFAS were studied and up to how many litres the reduction has actually been demonstrated.\n\n> **FREQUENTLY ASKED QUESTIONS** \n\n>**Is there PFAS in Dutch tap water?**
\nYes. Small amounts of PFAS can occur in Dutch tap water. The amount varies depending, among other things, on the source from which the drinking water is produced.\n\n>**Can I simply drink Dutch tap water?**
\nYes. According to the RIVM, Dutch tap water can simply be drunk. Average exposure to PFAS through drinking water alone is below the health-based limit value.\n\n>**How much PFAS may drinking water contain?**
\nSince 2026, a statutory standard of 100 ng/L for the sum of twenty PFAS has applied. In addition, the RIVM advises a health-based guideline value of 4.4 ng/L expressed in PFOA equivalents. These two values are calculated in different ways and are therefore not directly comparable.\n\n>**Do we mainly take in PFAS through tap water?**
\nNo. On average, food contributes more to exposure to PFAS than drinking water does.\n\n>**Can you filter PFAS out of tap water?**
\nYes. Activated carbon, ion exchange and reverse osmosis can reduce PFAS. How well a specific water filter does this has to be shown by independent laboratory tests. [Read our in-depth study: filtering PFAS out of tap water, what really works?](/uitleg/pfas-uit-kraanwater-filteren/)\n\n## Sources\n\n- [RIVM: PFAS in drinking water](https://www.rivm.nl/pfas/drinkwater)\n- [RIVM: PFAS in drinking water from river water must come down (2022)](https://www.rivm.nl/nieuws/pfas-in-drinkwater-uit-rivierwater-moet-omlaag)\n- [RIVM: New study confirms that people in the Netherlands take in too much PFAS (2023)](https://www.rivm.nl/nieuws/nieuw-onderzoek-bevestigt-mensen-in-nederland-krijgen-te-veel-pfas-binnen)\n- [RIVM: First national study of PFAS in blood](https://www.rivm.nl/nieuws/eerste-landelijke-onderzoek-naar-pfas-in-bloed)\n- [RIVM: PFAS dynamics in the Rhine and Meuse (2026)](https://www.rivm.nl/publicaties/pfas-dynamiek-in-rijn-en-maas-toekomstscenarios-met-simplebox)",
"product_ids": [],
"brand": null,
"created": "2026-10-16T08:42:16Z",
"updated": "2026-10-16T10:41:15Z"
},
{
"title": "Filtering PFAS from tap water: what really works?",
"titles": {
"en": "Filtering PFAS from tap water: what really works?",
"de": "PFAS aus Leitungswasser filtern: Was wirkt wirklich?",
"nl": "PFAS uit kraanwater filteren: wat werkt echt?"
},
"kicker": "Facts · PFAS explained · evidence",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/pfas-uit-kraanwater-filteren/",
"de": "https://waterfilterhouse.com/de/ratgeber/pfas-uit-kraanwater-filteren/",
"nl": "https://waterfilterhouse.com/nl/uitleg/pfas-uit-kraanwater-filteren/"
},
"url": "https://waterfilterhouse.com/en/guides/pfas-uit-kraanwater-filteren/",
"intro": "PFAS can be filtered out of tap water. Activated carbon, ion exchange and reverse osmosis in particular can reduce PFAS. However, how well a water filter does this depends heavily on the type of filter, the specific PFAS substance, the amount of water already filtered and the conditions in which the filter is used. So don't just look at the claim 'filters PFAS', but above all at independent test results.",
"body_markdown": "Dutch tap water is safe to drink. Even so, small amounts of PFAS can be present in it. If you want to reduce your exposure to PFAS even further, you can therefore opt for additional water filtration.\n\nBut which water filter actually works for this? And how do you know whether a filter really reduces PFAS?\n\nIn this guide we explain it.\n\n## What are PFAS?\n\nPFAS stands for **per- and polyfluoroalkyl substances.** It is a collective name for thousands of man-made chemicals.\n\nPFAS have been used, among other things, for their water-, grease- and dirt-repellent properties. They are or were found, for example, in certain coatings, textiles, packaging materials and fire-fighting foam.\n\nAn important property of many PFAS is that they are extremely difficult to break down. As a result, they can remain in the environment for a long time. That is why PFAS are also known as **'forever chemicals'**.\n\nVia soil, surface water and groundwater, PFAS can eventually end up in drinking water sources too.\n\n## Is there PFAS in Dutch tap water?\n\n**Yes, small amounts of PFAS can be present in Dutch tap water. That does not mean Dutch tap water is unsafe to drink.**\n\nAccording to the RIVM (the Dutch National Institute for Public Health and the Environment), people in the Netherlands take in PFAS through food and drinking water, among other routes. The average amount of PFAS that people take in through drinking water alone is below the health-based limit value.\n\nOn average, food contributes more to total PFAS exposure than drinking water does.\n\nThere is a difference, though, depending on where the drinking water comes from. Around 60% of Dutch drinking water is made from groundwater. According to the RIVM, drinking water from groundwater contains less PFAS on average than drinking water produced from surface water.\n\nThe RIVM advises reducing the amount of PFAS people are exposed to further wherever possible.\n\n## How much PFAS is allowed in drinking water?\n\nSince 2026, a legal limit of **100 nanograms per litre (ng/L)** has applied to twenty PFAS in drinking water. Dutch drinking water meets this legal standard.\n\nIn addition, the RIVM advises a considerably stricter health-based guideline value of:\n\n**4.4 ng/L expressed in PFOA equivalents (PEQ)**.\n\nThat last point is important to understand properly.\n\nIn water, PFAS usually occur as a mixture of different substances. One PFAS is not automatically as harmful as another. The RIVM therefore uses the so-called RPF method, which converts different PFAS into PFOA equivalents.\n\nThe legal standard of 100 ng/L and the RIVM guideline value of 4.4 ng/L PEQ are therefore **not directly comparable**: they are different ways of assessing the water.\n\n## Is it necessary to filter PFAS out of Dutch tap water?\n\nAs far as the safety of Dutch tap water is concerned, an extra water filter is not necessary. The RIVM and the Dutch government state that tap water can simply be drunk.\n\nThat is an important starting point.\n\nAt the same time, 'safe drinking water' does not mean that drinking water is completely free of PFAS. If you want to limit your personal exposure via drinking water further, you can choose to filter your tap water as an extra step.\n\nA water filter is therefore a **personal choice for further reduction**, and not a condition for being able to drink Dutch tap water safely.\n\n## Can you filter PFAS out of tap water?\n\n**Yes. Various filtration techniques can reduce PFAS in water.**\n\nThe US Environmental Protection Agency (EPA) names activated carbon, ion exchange and membrane techniques such as reverse osmosis in particular as options for PFAS reduction.\n\n| Filtration technique | PFAS reduction possible? | Note |\n|---|---|---|\n| Activated carbon | Yes | Effectiveness varies by PFAS and application |\n| Ion exchange | Yes | Can be very effective |\n| Reverse osmosis | Yes | Very effective technique |\n| Ordinary sediment filtration | Not specifically | Mainly intended for particles |\n| Ceramic filter alone | Not a given | Depends on additional filter media |\n\nIt is therefore too simple to claim that every carbon filter automatically removes all PFAS from water. The composition of the filter, the amount of filter material, the contact time and the specific PFAS all play a role.\n\n## How do activated carbon and ion exchange work against PFAS?\n\n### Activated carbon\n\nActivated carbon has a very large internal surface area to which certain substances can **adsorb**.\n\nAdsorption is not the same as absorption. Substances are not simply 'soaked up'; they attach themselves to the surface of the filter material.\n\nAccording to the EPA, granular activated carbon, often abbreviated to GAC, is one of the most thoroughly researched techniques for removing PFAS from drinking water.\n\nThere is an important nuance, though.\n\nActivated carbon generally works better against longer PFAS, such as PFOA and PFOS, than against some shorter PFAS. Its performance is also influenced by, among other things:\n\n- the type of carbon used;\n- the amount of filter material;\n- the contact time between water and filter;\n- the specific PFAS;\n- other substances present in the water;\n- the amount of water that has already passed through the filter.\n\n### Ion exchange\n\n**Ion exchange** can also be used to reduce PFAS in water. In this process, certain charged substances are bound to the filter medium.\n\nAccording to the EPA, ion exchange materials can be very effective at removing certain PFAS from water.\n\nHere too, actual performance depends on the filter material used, the specific PFAS and the conditions in which the filter is used.\n\nA filter that combines activated carbon and ion exchange can therefore use several filtration mechanisms. That does not automatically mean, however, that such a filter demonstrably reduces PFAS well.\n\nThat brings us back to the most important question:\n\n**Has the complete filter actually been tested for PFAS?**\n\n## And what about reverse osmosis?\n\nReverse osmosis, often abbreviated to **RO (Reverse Osmosis)**, works differently.\n\nIn RO, water is forced under pressure through a very fine membrane. Many dissolved substances cannot pass through this membrane, or can barely do so.\n\nThe EPA describes reverse osmosis as a very effective technique for reducing PFAS.\n\nHowever, RO has different characteristics from a gravity filter. A reverse osmosis system usually needs a connection to the water mains, produces a waste water stream and, besides unwanted substances, also removes a large share of the naturally occurring dissolved minerals.\n\nA gravity filter is much simpler to use. You fill the upper reservoir and gravity makes the water flow through the filter elements. No connection to the water mains or electricity is needed.\n\nWhich technique suits you best therefore depends not only on PFAS reduction, but also on what else you expect from a water filter.\n\n## Can a gravity water filter reduce PFAS?\n\n**Yes, but not every gravity filter does so automatically.**\n\nA gravity filter primarily describes the way the water is guided through the system. The actual filtering performance is determined by the **filter element inside the system**.\n\nA stainless steel housing naturally does not remove any PFAS. The filter element has to be suitable for that.\n\nOne example is the **BOROUX Foundation**. For the Foundation filter, BOROUX describes several filtration mechanisms, including activated carbon filtration and ion exchange. That combines two techniques that the EPA also names for PFAS reduction.\n\nOn its own, however, that is not yet proof of the filter's actual PFAS performance. That is why independent laboratory results matter more than the filtration technique used alone.\n\n## How well does BOROUX Foundation filter PFAS?\n\nThe **BOROUX Foundation filter** has been independently tested by IAPMO R&T Lab in New Jersey. The PFAS reduction was tested using the test methodology of **NSF/ANSI Standard 53**. The filter passed this PFAS reduction test up to a capacity of **400 gallons per filter element**, or roughly **1,514 litres**.\n\n**This means that the filter was tested according to this NSF/ANSI 53 test method. It does not mean that the BOROUX Foundation is fully NSF/ANSI 53 certified for PFAS.**\n\nWhat is particularly interesting is that the laboratory report does not only speak of 'PFAS' in general terms, but looked at several PFAS individually.\n\n| PFAS tested | Concentration before filtration* | Concentration after 400 gallons* | Result |\n|---|---:|---:|---|\n| PFOA | 0.50 µg/L | 0.01 µg/L | approx. 98% reduction |\n| PFOS | 1.10 µg/L | 0.01 µg/L | approx. 99.1% reduction |\n| PFOA + PFOS | 1.60 µg/L | 0.02 µg/L | approx. 98.8% reduction |\n| PFNA | 0.05 µg/L | <0.001 µg/L | >98% reduction |\n| PFHxS | 0.29 µg/L | <0.01 µg/L | >96.5% reduction |\n| PFHpA | 0.04 µg/L | <0.01 µg/L | >75% reduction |\n| PFBS | 0.28 µg/L | Not reported** | No separate reduction percentage available |\n| PFDA | 0.01 µg/L | Not reported** | No separate reduction percentage available |\n| **Total PFAS** | **2.27 µg/L** | **0.02 µg/L** | **approx. 99.1% reduction** |\n\n*Values at the measuring point after 400 gallons, roughly 1,514 litres, per filter element. A `<` value means that the measured concentration was below the stated reporting or detection limit.*\n\n** PFBS and PFDA were included in the laboratory test and the report states influent values for them. However, no effluent concentrations are reported for these two individual PFAS. A separate reduction percentage for PFBS and PFDA therefore cannot be calculated from the published report. Both substances were, however, included in the total PFAS measurement.\n
\n
\n
\nIn the total PFAS measurement, the concentration before filtration was **2.27 µg/L**. After 400 gallons of filtration, **0.02 µg/L** was measured.\n\nAt the end of the tested capacity, that amounts to a reduction of roughly:\n\n**99.1% of the total tested PFAS concentration.**\n\nWe consider that an important detail. The percentage is based on the measurement after **400 gallons (roughly 1,514 litres)**, and not just on the performance of a new filter at the start of the test.\n\n## Does 99.1% mean that BOROUX always removes 99.1% of all PFAS?\n\n**No.**\n\nWe think this distinction is important.\n\nThe laboratory test shows how the BOROUX Foundation filter performed with the PFAS tested under set test conditions. It does not mean that exactly the same reduction percentage will be achieved in every real-life situation.\n\nActual performance can vary because of, among other things:\n\n- the composition and quality of the water;\n- the concentration of PFAS;\n- other substances present in the water;\n- the amount of water that has already passed through the filter;\n- the conditions of use.\n\nIn addition, PFAS is a collective name for thousands of different substances. The fact that a filter demonstrably reduces several PFAS therefore does not automatically mean that the same reduction percentage applies to every PFAS that exists.\n\nThat is why we find the wording:\n\n**'BOROUX Foundation reduced roughly 99.1% of the total tested PFAS concentration at the end of the independent laboratory test'**\n\nmore accurate than:\n\n**'BOROUX removes 99.1% of all PFAS.'**\n\nThat difference may seem small, but it matters if you want to compare water filters fairly and on the basis of measurable results.\n\n## How long does a filter keep reducing PFAS?\n\nA reduction percentage says little unless you know **up to how many litres the filter was tested**.\n\nThe BOROUX Foundation PFAS test ran up to **400 gallons per filter element**, or about **1,514 litres**.\n\nWhen two Foundation filter elements are used, this corresponds to a tested PFAS capacity of about **800 gallons, or 3,028 litres per pair**.\n\nThat does not mean a filter suddenly stops reducing PFAS after exactly 3,028 litres. It does mean that, for a well-founded PFAS claim, you should not simply state a larger capacity than the one for which the performance has actually been demonstrated.\n\nThis is also why a single general lifespan for a water filter can be misleading. The tested capacity can **differ per contaminant**.\n\nA filter may, for example, have been tested for chlorine up to a much larger volume of water than for PFAS. If you specifically want to reduce PFAS, you are well advised to look at the **capacity tested for PFAS** and not only at the filter's general maximum lifespan.\n\n## What should you look out for when buying a water filter for PFAS?\n\nDon't just look at big claims on a package or in an online shop. Ask a few concrete questions instead:\n\n**1. Has the filter actually been tested for PFAS?**\n\n'Contains activated carbon' is not, on its own, proof of the PFAS performance of a complete filter.\n\n**2. Which PFAS were tested?**\n\nA test on PFOA and PFOS alone is something different from a test in which several PFAS are included individually.\n\n**3. Who carried out the test?**\n\nA test by an independent laboratory gives you more to go on than a claim from the manufacturer alone.\n\n**4. Up to how many litres was the filter tested?**\n\nAn impressive reduction percentage at the start of the filter's life does not yet tell you how the filter performs later on. So also look at the measurements at the end of the tested capacity.\n\n**5. What was the concentration before and after filtration?**\n\nWith these values you can judge far better what was actually measured than with a rounded reduction percentage alone.\n\n**6. Has the filter been tested or certified?**\n\nThose are not automatically the same thing. A product can be independently tested according to a particular NSF/ANSI test method without the complete product being NSF certified for that claim.\n\n## So what is the best water filter against PFAS?\n\nThere is no single water filter that is the best choice for everyone.\n\nIf you want the widest possible removal of dissolved substances and you don't mind a fixed installation and waste water, **reverse osmosis** may be interesting.\n\nIf, on the other hand, you want a simple system without electricity and without a connection to the water mains, a **gravity water filter with filter elements demonstrably tested for PFAS** may be an interesting choice.\n\nUltimately, what matters most is not just the name of the technique or the brand.\n\n**The test results of the specific filter element must support the claim.**\n\n## Conclusion\n\n**PFAS can be reduced in tap water. Activated carbon, ion exchange and reverse osmosis are among the techniques used for this.**\n\nDutch tap water meets the legal requirements and can be drunk safely. An extra water filter is therefore not necessary to make tap water safe. People can, however, choose to reduce their exposure to PFAS via drinking water even further.\n\nIf you are buying a water filter for this purpose, you are well advised to look beyond the general claim *'filters PFAS'*.\n\nLook at:\n\n- which PFAS were tested;\n- how much was reduced;\n- who carried out the test;\n- under which conditions it was tested;\n- up to how many litres that performance has been demonstrated.\n\nFor BOROUX Foundation, for example, an independent laboratory test has shown that at the end of the tested capacity of **400 gallons per filter element, the filter reduced roughly 99.1% of the total tested PFAS concentration**.\n\nMeasurable data of this kind makes it possible to compare water filters in a much fairer way.\n\n\n> **FREQUENTLY ASKED QUESTIONS ABOUT PFAS AND WATER FILTERS** \n\n>**Is there PFAS in Dutch tap water?**
\nYes. Small amounts of PFAS can be present in Dutch drinking water. According to the RIVM, average exposure through drinking water alone is below the health-based limit value, and Dutch tap water can simply be drunk.\n\n>**Can activated carbon remove PFAS?**
\nActivated carbon can reduce PFAS in water. However, its effectiveness varies by PFAS, filter material, contact time and conditions of use. Longer PFAS such as PFOA and PFOS are generally adsorbed better by activated carbon than some shorter PFAS.\n\n>**Can ion exchange remove PFAS from water?**
\nYes. Ion exchange can effectively reduce certain PFAS in water. In this process, PFAS are bound to a special filter material. According to the EPA, ion exchange, alongside activated carbon and reverse osmosis, is one of the techniques that can be used for PFAS reduction. Actual effectiveness depends on the filter material used, the specific PFAS and the conditions in which the filter is used.\n\n>**Does reverse osmosis remove PFAS?**
\nAccording to the EPA, reverse osmosis is a very effective technique for reducing PFAS. An RO system also removes many other dissolved substances and a large share of the naturally occurring dissolved minerals.\n\n>**Does BOROUX filter PFAS?**
\nYes. BOROUX Foundation has been tested by IAPMO R&T Lab for PFAS reduction according to the test methodology of NSF/ANSI Standard 53. At the end of the test, after 400 gallons per filter element, a reduction of roughly **99.1%** was measured for the total tested PFAS concentration.\nThis does not mean that BOROUX Foundation is fully NSF/ANSI 53 certified for PFAS. It means that the PFAS performance has been independently tested according to this test methodology.\n\n>**Does every gravity filter remove PFAS?**
\nNo. 'Gravity filter' mainly describes how the water flows through the system. The actual reduction of PFAS depends on the filter element used. So check the independent test results of the specific filter.\n\n>**Do I need a water filter to drink Dutch tap water safely?**
\nNo. The Dutch government and the RIVM state that Dutch tap water can simply be drunk. An additional water filter can be used, however, if someone wants to reduce certain substances, such as PFAS, even further.\n\n## Sources\n\n- [RIVM – PFAS in drinking water - Information on PFAS in Dutch drinking water, exposure, legal requirements and the health-based guideline value](https://www.rivm.nl/pfas/drinkwater)\n- [RIVM – Method for assessing PFAS in drinking water samples - Explanation of the guideline value of 4.4 ng/L PFOA equivalents and the RPF method](https://www.rivm.nl/publicaties/werkwijze-toetsing-pfas-in-drinkwatermonsters)\n- [Rijksoverheid – Is there PFAS in drinking water? - Information from the Dutch government on PFAS and the safety of Dutch tap water](https://www.rijksoverheid.nl/vraag-en-antwoord/pfas/zitten-er-pfas-in-het-drinkwater)\n- [US Environmental Protection Agency – Reducing PFAS in Drinking Water with Treatment Technologies - Information on activated carbon, ion exchange, nanofiltration and reverse osmosis](https://www.epa.gov/sciencematters/reducing-pfas-drinking-water-treatment-technologies)\n- [US Environmental Protection Agency – Identifying Drinking Water Filters Certified to Reduce PFAS - Explanation of the certification of water filters for PFAS reduction, including NSF/ANSI 53 for filters and NSF/ANSI 58 for reverse osmosis. The EPA also explains what such a certification does and does not say about actual PFAS reduction](https://www.epa.gov/water-research/identifying-drinking-water-filters-certified-reduce-pfas)\n- [IAPMO R&T Lab – BOROUX Foundation PFAS Reduction Test, Report #23-199-2-PFAS - Independent laboratory test according to NSF/ANSI Standard 53 for PFAS reduction](https://boroux.com/pages/what-does-boroux-foundation-filter-remove)",
"product_ids": [
81461,
81515,
81463,
81542,
81489,
81525,
81464,
81545,
81490
],
"brand": null,
"created": "2026-10-16T08:42:16Z",
"updated": "2026-10-16T10:43:45Z"
},
{
"title": "BOROUX: the successor to Berkey that Europe has yet to discover",
"titles": {
"en": "BOROUX: the successor to Berkey that Europe has yet to discover",
"de": "BOROUX: der Nachfolger von Berkey, den Europa erst noch entdecken muss",
"nl": "BOROUX: de opvolger van Berkey die Europa nog moet ontdekken"
},
"kicker": "Guide · BOROUX water filter",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/boroux-waterfilter/",
"de": "https://waterfilterhouse.com/de/ratgeber/boroux-waterfilter/",
"nl": "https://waterfilterhouse.com/nl/uitleg/boroux-waterfilter/"
},
"url": "https://waterfilterhouse.com/en/guides/boroux-waterfilter/",
"intro": "The same filter formula, a new brand and its own systems in four colours. And the only BOROUX dealer in Europe is based right in Hegelsom (the Netherlands).",
"body_markdown": "## Where BOROUX comes from\n\nWhen the US environmental agency EPA halted the individual sale of Black Berkey elements in early 2023, it left a gap: millions of households with a stainless steel housing that lasts for decades, and no more elements to put in it. The answer did not come from Berkey itself, but from two parties who knew the product inside out: the team behind the largest American Berkey dealer and the factory that had made the original Black Berkey formula all those years. Together they started a new brand: BOROUX. You can read the full story about that American decision in [the Black Berkey explainer](/uitleg/black-berkey-alternatief/).\n\n## The same formula, neatly within the rules\n\nThe **BOROUX Foundation Black** filters use the same basic formula of, among other things, compressed activated carbon as the original Black Berkey elements, made in the same place in America, with new patented improvements. The difference lies in the registration: BOROUX makes no claims about micro-organisms (bacteria and viruses), and therefore falls outside the American pesticides act that proved Berkey's undoing. The elements have also been tested by the independent IAPMO laboratory and certified by WQA to NSF/ANSI 42 (taste, odour, particulates), NSF/ANSI 372 (lead-free material) and NSF/ANSI 401 (microplastics); the test reports per substance are simply online, in [the shop's library](https://www.alternatievemiddelen.nl/veelgestelde-vragen-boroux-waterfilters/?utm_source=helder&utm_medium=companion&utm_campaign=poc).\n\n## Its own systems, four colours\n\nBOROUX did not stop at individual filter elements. The **Legacy** (11.4 litres) and **Legacy Compact** (6.8 litres) are complete systems made of food-safe stainless steel (AISI 304), supplied as standard with two BOROUX Foundation elements. And because BOROUX supplied directly to end customers for years, they know what people want besides performance: the systems also come in white, black and sage green, with matching stainless steel taps and sight glass taps. A water filter you do not have to hide away.\n\n## Honest about fluoride\n\nThe BOROUX Foundation elements do not filter fluoride; that emerged from the first tests and BOROUX says so plainly. Of course, this was the same with the Black Berkey filters. If you want to reduce fluoride, fit the powerful **ProActive Fluoride** filters underneath: one per Foundation element, with an upflow design that guides the water from the bottom to the top. So without coming into contact with the filtered water and without the use of aluminium oxide. This is, then, in contrast to Berkey's fluoride filters. And the best part: they also fit directly onto Black Berkey elements in an existing Berkey system.\n\n## And Europe?\n\nHere it gets special: in the whole of Europe there is exactly one official BOROUX dealer, and it is based in Hegelsom (the Netherlands). Alternatievemiddelen.nl brought the brand to the Netherlands, primes the elements for you if you wish (or you can use the electric priming pump: ninety seconds per element) and simply answers questions via WhatsApp. Anyone in Europe who buys a BOROUX buys it from Tom and Melanie.\n\n> **In short.** BOROUX = the original Black Berkey formula, continued by the people who made and sold it, without the legal baggage. Elements fit in any Berkey housing, its own systems come in four colours, test reports are public, and the only European dealer is in the Netherlands.",
"product_ids": [
81461,
81515,
81463,
81542,
81489,
81525,
81464,
81545,
81490,
81467,
81468,
81506
],
"brand": null,
"created": "2026-10-16T08:42:16Z",
"updated": "2026-10-16T10:46:10Z"
},
{
"title": "ProOne disappeared: the real element is called Coldstream FTO PLUS",
"titles": {
"en": "ProOne disappeared: the real element is called Coldstream FTO PLUS",
"de": "ProOne ist verschwunden: Das echte Element heißt Coldstream FTO PLUS",
"nl": "ProOne verdween: het echte element heet Coldstream FTO PLUS"
},
"kicker": "Guide · proone filter alternative",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/proone-alternatief-coldstream/",
"de": "https://waterfilterhouse.com/de/ratgeber/proone-alternatief-coldstream/",
"nl": "https://waterfilterhouse.com/nl/uitleg/proone-alternatief-coldstream/"
},
"url": "https://waterfilterhouse.com/en/guides/proone-alternatief-coldstream/",
"intro": "ProOne was taken over in America, but the famous filter element comes from an English factory and is still around, under its own name. This is how your system keeps running.",
"body_markdown": "## What happened to ProOne\n\nFor years ProOne was the price-conscious choice among gravity filters: a powerful all-in-one ceramic element, no fuss with priming or with additional fluoride filters. Until the company was taken over in America, stopped selling through dealers and the brand as customers knew it disappeared from the market. If you now have a ProOne Traveler+, Big + or Big II water filter (or even older ProOne models) on your worktop, you will no longer find a box with that logo on it anywhere.\n\n## The element has existed longer than the brand\n\nHere is the reassurance: the filter element that made ProOne big, the G2.0, was never made by ProOne itself. It came from an English factory, and it is still rolling off the production line there, under its own name: **Coldstream FTO PLUS**. Same ceramic element, same factory, only the brand sticker of the middleman is gone.\n\n## What the Coldstream can do\n\nIt is a ceramic element with a filled core, which makes it low-maintenance: **priming is not needed**, and neither are separate fluoride add-on filters, because fluoride reduction is already built in. Its lifespan is 1,500 litres or six months (whichever comes first); cleaning it once a month together with the chambers is all the maintenance there is. The test reports and manuals can be found in [the library of Alternatievemiddelen.nl](https://www.alternatievemiddelen.nl/veelgestelde-vragen-coldstream-fto-plus-waterfilter-elementen/?utm_source=helder&utm_medium=companion&utm_campaign=poc).\n\n## Does it fit my ProOne?\n\nYes: the Coldstream FTO PLUS is the direct successor in every ProOne Traveler+, Big+ and Big II water filter. And unfortunately also No: for the ProOne Scout II and the ProOne water filter jug there is no successor; sales of these were so minimal at ProOne that Coldstream can no longer produce these filters. Get in touch with [Alternatievemiddelen.nl](https://www.alternatievemiddelen.nl/contact/) for advice on alternatives.\nAnd if you are ready for a whole new system, you do not have to give up the shape: the **Pure Filters** systems (Voyager 6L, Home 9L and Family 12L) are supplied as standard with two Coldstream FTO PLUS elements. Replacing the filters after that is always the same, every 6 months.\n\n> **In short.** ProOne disappeared, the element did not. It is called Coldstream FTO PLUS, comes from the same English factory, fits your existing ProOne Traveler+, Big+ or Big II system and is fitted as standard in the Pure Filters systems. No priming, fluoride included, replace every six months.",
"product_ids": [
81536,
81457,
81537,
81456
],
"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "Filtering medicine residues from tap water: what really works?",
"titles": {
"en": "Filtering medicine residues from tap water: what really works?",
"de": "Arzneimittelrückstände aus Leitungswasser filtern: Was wirkt wirklich?",
"nl": "Medicijnresten uit kraanwater filteren: wat werkt echt?"
},
"kicker": "Facts · medicine residues explained · evidence",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/medicijnresten-uit-kraanwater-filteren/",
"de": "https://waterfilterhouse.com/de/ratgeber/medicijnresten-uit-kraanwater-filteren/",
"nl": "https://waterfilterhouse.com/nl/uitleg/medicijnresten-uit-kraanwater-filteren/"
},
"url": "https://waterfilterhouse.com/en/guides/medicijnresten-uit-kraanwater-filteren/",
"intro": "Medicine residues can be reduced in tap water. Activated carbon and reverse osmosis in particular can reduce various medicine residues. How well a water filter does this differs per substance and per filter. Independent laboratory tests of the complete filter therefore give you more information than the mere claim that a filter 'removes medicine residues'.",
"body_markdown": "Very small amounts of medicine residues or breakdown products are sometimes found in Dutch tap water. According to the RIVM (the Dutch National Institute for Public Health and the Environment), these concentrations are far below the levels at which health effects are expected in humans.\n\nAn additional water filter is therefore **not needed to drink Dutch tap water safely**. If you want to reduce the amount of unwanted substances in your drinking water even further, you can of course choose to do so.\n\n## How do medicine residues end up in our water?\n\nAfter use, medicines are not always completely broken down by the body. Residues can end up in the sewer via urine and faeces. Medicines applied to the skin, such as certain creams and ointments, can also end up in waste water when we wash.\n\nSewage treatment plants remove some of these substances, but not all of them. They are simply not designed specifically to remove all micropollutants.\n\nAs a result, medicine residues eventually end up in surface water.\n\nAccording to the RIVM, **at least 190 tonnes of medicine residues reach surface water** in the Netherlands every year. The actual amount may be higher, because, among other things, over-the-counter medicines, medicines from specialist care and certain breakdown products are not fully included in this estimate.\n\n## Are there medicine residues in Dutch tap water?\n\n**Yes, very small amounts are sometimes found.**\n\nDutch drinking water is made from groundwater and surface water. According to the RIVM, medicine residues are found more often, and in higher concentrations, in surface water sources than in groundwater sources.\n\nDuring drinking water treatment, the concentrations are reduced considerably. Even so, tiny amounts of medicine residues or breakdown products can sometimes still be found.\n\nThe RIVM mentions, for example:\n\n- metformin;\n- iomeprol;\n- guanylurea, a breakdown product.\n\nAccording to the RIVM, the concentrations found are **far below the concentrations at which health effects are expected in humans**.\n\n## Why are medicine residues still a problem?\n\nThe main concern at the moment is not the safety of Dutch tap water, but the **aquatic environment and our drinking water sources**.\n\nMedicines are biologically active substances. In Dutch surface water, for example, painkillers, antibiotics, blood pressure medication, antidepressants and anti-epileptics have been found.\n\nFor several substances, concentrations are measured that are above the risk limits for organisms living in the water.\n\nIn addition, a heavier load on rivers and other drinking water sources means that water companies have to make more effort to produce clean drinking water.\n\n## Can you filter medicine residues out of tap water?\n\n**Yes. Various filtration techniques can reduce medicine residues.**\n\nMedicine residues are not a uniform group, however. Medicines differ greatly in their chemical properties. A filter that reduces one medicine very well does not automatically reduce every other medicine equally well.\n\n| Filtration technique | Reduces medicine residues? | Note |\n|---|---|---|\n| Activated carbon | Yes | Effectiveness varies by medicine and filter |\n| Reverse osmosis | Yes | Can greatly reduce many dissolved micropollutants |\n| Sediment filter | Not specifically | Mainly intended for suspended particles |\n| Ceramic alone | Not a given | Performance depends on the complete filter element |\n\nThat is why the question *'does this system filter medicine residues?'* is actually too general.\n\nA better question is:\n\n**Which medicine residues were actually tested, how much of them was reduced, and up to what filter capacity?**\n\n## How does activated carbon work against medicine residues?\n\nActivated carbon has a very large internal surface area. Various organic substances can attach themselves to it. This process is called **adsorption**.\n\nMany organic micropollutants, including various medicine residues, can be reduced this way.\n\nPerformance depends, among other things, on:\n\n- the specific medicine;\n- the filter material used;\n- the amount of filter material;\n- the contact time with the water;\n- other substances in the water;\n- the amount of water that has already been filtered.\n\nThe mere presence of activated carbon therefore does not prove how well a complete water filter reduces medicine residues.\n\n## Does reverse osmosis work against medicine residues?\n\n**Yes. Reverse osmosis can greatly reduce many medicine residues and other dissolved micropollutants.**\n\nIn reverse osmosis, often abbreviated to RO, water is forced under pressure through a very fine membrane.\n\nAn RO system does have different characteristics from, say, a gravity filter. It is usually connected to the water mains, produces a waste water stream and, besides unwanted substances, also removes a large share of the naturally occurring dissolved minerals.\n\n## Which water filters have actually been tested for medicine residues?\n\nFor consumers it is hard to tell how well a filter works from the filter material used alone.\n\nThat is why we prefer to look at independent laboratory tests of the **complete filter element**.\n\nTwo examples for which extensive test results are available are the **BOROUX Foundation and Coldstream FTO Plus**.\n\n## BOROUX Foundation and medicine residues\n\nThe BOROUX Foundation has been examined by **IAPMO R&T Lab in New Jersey**, using the **NSF/ANSI 401 test methodology**, for pharmaceutical substances and other so-called *emerging compounds*.\n\nThe published results include eight pharmaceutical substances.\n\n| Substance tested | Concentration before filtration | Average after filtration | Calculated reduction | Tested up to* |\n|---|---:|---:|---:|---:|\n| Atenolol | 200 ng/L | 12 ng/L | 94.0% | 200 gallons |\n| Carbamazepine | 1,400 ng/L | 42 ng/L | 97.0% | 250 gallons |\n| Estrone | 140 ng/L | 3 ng/L | 97.9% | 250 gallons |\n| Ibuprofen | 400 ng/L | 22 ng/L | 94.5% | 200 gallons |\n| Meprobamate | 400 ng/L | 14 ng/L | 96.5% | 200 gallons |\n| Naproxen | 140 ng/L | 2 ng/L | 98.6% | 250 gallons |\n| Phenytoin | 200 ng/L | 3 ng/L | 98.5% | 250 gallons |\n| Trimethoprim | 140 ng/L | 6 ng/L | 95.7% | 250 gallons |\n\n\\*The capacity stated applies per BOROUX Foundation filter element tested. 200 gallons is about 757 litres and 250 gallons about 946 litres.\n\nThe reduction percentages in the table above have been calculated from the concentrations before and after filtration published in the laboratory report.\n\n## What does the tested capacity mean?\n\nThe 200 and 250 gallons mentioned are **test capacities, not prescribed replacement points**.\n\nDuring laboratory tests, fixed concentrations of the substances under investigation are used. These test concentrations can be considerably higher than the very small amounts of medicine residues found in Dutch tap water.\n\nA test up to 250 gallons, for example, therefore does not mean that the filter has to be replaced after 250 gallons, or that it stops working after that. Conversely, the difference in concentration cannot be used to calculate how much longer a filter will last in Dutch tap water. Filter capacity is influenced by the full composition of the water, not just by a single medicine residue.\n\n**There is therefore no universal replacement interval for the reduction of all substances**. Actual performance depends on, among other things, the concentrations of substances in the water, the overall composition of the water, usage and the amount of water that has passed through the filter.\n\nIt is also important that **tested according to NSF/ANSI 401 does not automatically mean the same as fully NSF/ANSI 401 certified for every reduction claim**.\n\nThe results do show how the complete BOROUX Foundation filter performed under the defined test conditions for the eight pharmaceutical substances examined.\n\n## Coldstream FTO Plus and medicine residues\n\nThe **Coldstream FTO Plus (CF163W) filter element** has also been extensively tested.\n\nThe published performance report contains results for **30 substances that the report lists under the category 'Pharmaceuticals'**. These include various medicines, but also other organic micropollutants.\n\nA selection of the medicines actually tested:\n\n| Substance tested | Concentration before filtration | After 3,000 litres | Reduction |\n|---|---:|---:|---:|\n| Ibuprofen | 418 µg/L | 3.2 µg/L | 99.23% |\n| Trimethoprim | 133 µg/L | <0.01 µg/L | >99.99% |\n| Naproxen | 182 µg/L | <0.01 µg/L | >99.99% |\n| Acetaminophen (paracetamol) | 273 µg/L | <0.01 µg/L | >99.99% |\n| Ciprofloxacin | 1,041 µg/L | <0.01 µg/L | >99.99% |\n| Sulfamethoxazole | 186 µg/L | <0.01 µg/L | >99.99% |\n| Fluoxetine | 1.83 µg/L | <0.01 µg/L | >99.45% |\n| Diclofenac | 206 µg/L | <0.01 µg/L | >99.99% |\n| Carbamazepine | 1,842 µg/L | <0.01 µg/L | >99.99% |\n| Phenytoin | 191 µg/L | <0.01 µg/L | >99.99% |\n| Meprobamate | 449 µg/L | 12.6 µg/L | 97.19% |\n| Atenolol | 209 µg/L | <0.01 µg/L | >99.99% |\n\nThis is only a selection. The report also contains results for estrone, estradiol, gemfibrozil and primidone, among others.\n\nHere too, the test capacity matters.\n\nThe **3,000 litres is the measuring point of these laboratory results and not automatically the recommended service life of the filter**. For the FTO Plus filter, the performance document states a *rated capacity* of **1,500 litres** and advises replacing the filter at least every six months.\n\nThe laboratory test therefore shows what was measured at 3,000 litres under the test conditions in question. It should not be concluded from this that the manufacturer recommends a service life of 3,000 litres.\n\n## BOROUX Foundation or Coldstream FTO Plus for medicine residues?\n\nBoth filters have laboratory data showing that various medicine residues can be greatly reduced.\n\nA direct comparison based on the percentages alone is not entirely fair, however. The concentrations used, test methods, test set-ups and capacities differ.\n\nThere are clear differences in the data available, though:\n\n- **BOROUX Foundation** was examined according to the NSF/ANSI 401 test methodology for eight pharmaceutical substances. For each substance, the published results state the concentration before and after filtration and a tested capacity of 200 or 250 gallons per filter element.\n- **Coldstream FTO Plus** has a broader published list of results, covering 30 substances that the laboratory report lists under the category 'Pharmaceuticals'. These include various medicines. The performance report contains measurements at 3,000 litres. The stated service capacity of the filter itself is 1,500 litres.\n\nThe same starting point therefore applies to both:\n\n**Don't just look at the highest reduction percentage, but also at the specific substance, the test conditions and the amount of water at which the performance was examined.**\n\n## Do laboratory results mean you will get exactly the same percentage at home?\n\n**No.**\n\nLaboratory tests are valuable because a filter is examined under controlled and reproducible conditions. To measure performance properly, fixed concentrations of the substances under investigation are added to the test water.\n\nThe composition of Dutch tap water is different, and the concentrations of medicine residues found in it are usually much lower.\n\nActual performance and service life can be influenced by, among other things:\n\n- the composition of the tap water;\n- the concentration of a particular substance;\n- other substances in the water;\n- the amount of water that has already passed through the filter;\n- the flow rate;\n- use and maintenance.\n\nA laboratory result therefore shows how the filter performed **under the test conditions described**. It is no guarantee that exactly the same reduction percentage or capacity will be achieved at home.\n\n## What should you look out for with a water filter for medicine residues?\n\nPay particular attention to these points:\n\n**1. Which substances were actually tested?**
\nA test on ibuprofen does not automatically say anything about every other medicine.
\n**2. Has the complete filter been tested?**
\nA general property of activated carbon is less specific than a laboratory test of the actual filter element.
\n**3. Who carried out the test?**
\nIndependent laboratory results give you more to go on than a claim from a manufacturer or seller alone.
\n**4. Up to how many litres was it tested?**
\nA reduction percentage is more informative when it is also clear how much water passed through the filter during the test. This is not automatically the point at which the filter has to be replaced in practice.
\n**5. Is it about testing or certification?**
\nTested according to an NSF/ANSI standard and NSF/ANSI certified do not mean the same thing.
\n\n## Is a water filter against medicine residues necessary in the Netherlands?\n\n**No. An additional water filter is not necessary to drink Dutch tap water safely.**\n\nAccording to the RIVM, medicine residues currently pose no threat to the quality of Dutch drinking water. The amounts sometimes found in drinking water are far below the concentrations at which health effects are expected.\n\nIf you want to reduce your exposure to certain unwanted substances even further, you can choose additional filtration.\n\nIn that case, we advise above all looking at the **laboratory results of the specific filter**.\n\n## Conclusion\n\n**Medicine residues can occur in very small amounts in Dutch tap water, but according to the RIVM, the current concentrations pose no threat to the quality of drinking water.**\n\nIf you still want to reduce medicine residues further, you can opt for additional water filtration. Activated carbon and reverse osmosis can reduce various medicine residues.\n\nNot every filter and not every medicine residue behaves in the same way, however.\n\nThe BOROUX Foundation and Coldstream FTO Plus are examples of filters for which extensive laboratory data is available. BOROUX Foundation was examined according to the NSF/ANSI 401 test methodology for eight pharmaceutical substances. For Coldstream FTO Plus, results have been published for 30 substances that the laboratory report lists under the category 'Pharmaceuticals', including various medicines.\n\nThat is why we prefer to look at **actual laboratory results per substance** rather than at the general claim that a water filter 'removes medicine residues'.\n\n\n\n> **FREQUENTLY ASKED QUESTIONS** \n\n>**Are there medicine residues in Dutch tap water?**
\nYes. Very small amounts of medicine residues or breakdown products are sometimes found in Dutch drinking water. According to the RIVM, these concentrations are far below the levels at which health effects are expected in humans.\n\n>**Is Dutch tap water unhealthy because of medicine residues?**
\nNo. According to the RIVM, medicine residues currently pose no threat to the quality of Dutch drinking water.\n\n>**Can activated carbon filter medicine residues out of water?**
\nYes. Activated carbon can reduce various organic micropollutants, including certain medicine residues. Effectiveness varies by substance and by filter.\n\n>**Can reverse osmosis remove medicine residues?**
\nYes. Reverse osmosis can greatly reduce many dissolved micropollutants. Actual performance varies by substance and system.\n\n>**Does BOROUX Foundation filter medicine residues?**
\nYes. BOROUX Foundation has been examined by IAPMO R&T Lab, using the NSF/ANSI 401 test methodology, for eight pharmaceutical substances. The published results show strong reductions for the substances examined.
\nThe test capacity of 200 or 250 gallons does not mean the filter then has to be replaced automatically. The test concentrations and conditions differ from Dutch tap water, and the actual service life depends on the composition of the water and on use.\n\n>**Does Coldstream FTO Plus filter medicine residues?**
\nYes. Laboratory results have been published for various medicines for the Coldstream FTO Plus CF163W filter. At the 3,000 litre measuring point, reductions of more than 99% were measured for many of the medicines examined.
\nThe 3,000 litres is a measuring point from the laboratory test and not the recommended service life. The stated service capacity of the filter is 1,500 litres.\n\n>**Does every gravity filter remove medicine residues?**
\nNo. How well it works is determined mainly by the filter element used, and not by the fact that water flows through the system by gravity. So look at the test results of the specific filter.\n\n>**Is a water filter needed because of medicine residues?**
\nNo. According to the RIVM, Dutch tap water can be drunk safely. An additional filter is a personal choice if you want to reduce certain unwanted substances even further.\n\n## Sources\n\n- [RIVM: Medicines and the environment](https://www.rivm.nl/medicijnen-en-het-milieu)\n- [RIVM: How do medicines end up in the environment?](https://www.rivm.nl/medicijnen-en-het-milieu/hoe-komen-medicijnen-in-het-milieu-terecht)\n- [RIVM: Effects on drinking water and drinking water sources](https://www.rivm.nl/medicijnen-en-het-milieu/effecten-op-drinkwater-en-drinkwaterbronnen)\n- [RIVM: Medicine residues and water quality, an update](https://www.rivm.nl/publicaties/medicijnresten-en-waterkwaliteit-update)\n- [BOROUX Foundation: overview of independent laboratory tests](https://boroux.com/pages/what-does-boroux-foundation-filter-remove)\n- [IAPMO R&T Lab: BOROUX Foundation NSF/ANSI 401 Group 1](https://www.alternatievemiddelen.nl/wp-content/uploads/2025/05/Testrapport-BOROUX_-_Pharma-GI.pdf)\n- [IAPMO R&T Lab: BOROUX Foundation NSF/ANSI 401 Group 2](https://www.alternatievemiddelen.nl/wp-content/uploads/2025/05/Testrapport-BOROUX_-_Pharma-G2.pdf)\n- [IAPMO R&T Lab: BOROUX Foundation NSF/ANSI 401 Group 3](https://www.alternatievemiddelen.nl/wp-content/uploads/2025/05/Testrapport-BOROUX_-_Pharma-G3.pdf)\n- [Coldstream FTO Plus CF163W: Performance Data Sheet](https://www.alternatievemiddelen.nl/wp-content/uploads/2026/10/Coldstream-FTO-PLUS-filterelementen_testrapport.pdf)",
"product_ids": [
81536,
81461
],
"brand": null,
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:43:45Z"
},
{
"title": "British Berkefeld stopped selling through dealers: this is how your system keeps running",
"titles": {
"en": "British Berkefeld stopped selling through dealers: this is how your system keeps running",
"de": "British Berkefeld hat den Händlerverkauf eingestellt: So läuft Ihr System weiter",
"nl": "British Berkefeld stopte met dealers: zo draait jouw systeem door"
},
"kicker": "Guide · british berkefeld alternative",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/british-berkefeld-alternatief/",
"de": "https://waterfilterhouse.com/de/ratgeber/british-berkefeld-alternatief/",
"nl": "https://waterfilterhouse.com/nl/uitleg/british-berkefeld-alternatief/"
},
"url": "https://waterfilterhouse.com/en/guides/british-berkefeld-alternatief/",
"intro": "The brand still exists, but no longer sells through (online) shops. The Coldstream FTO PLUS fits the same housing and filters more. The honest switching story.",
"body_markdown": "## What changed\n\nBritish Berkefeld still exists; a few years ago the company simply decided to stop selling through dealers and to sell everything itself from England. For Dutch owners that meant: no more shop that knows your system and keeps the filter elements in stock as standard with fast delivery, and no more regular point of contact who thinks along when something is wrong. Whereas the stainless steel housing of a Berkefeld can last for decades.\n\n## The switch customers have already made\n\nAlternatievemiddelen.nl has therefore moved its own Berkefeld customers over, step by step, to the element that did remain readily available: the ceramic **Coldstream FTO PLUS**, from the English factory that also made the famous ProOne elements. It fits the same housing, and the test reports show that it reduces more contaminants than the British Berkefeld filters (Ultra Sterasyl and Ultra Fluoride), including fluoride directly, so you no longer have to choose between two variants. Switching is literally this: old elements out, Coldstream in.\n\n## What you keep and what you gain\n\nYou keep your system, your tap and your place on the worktop. You gain simplicity: you no longer have to choose between variants and it also filters fluoride directly. The Coldstream filters do not need to be primed (made ready for use) either, just as you are used to with the British Berkefeld filters (Ultra Sterasyl and Ultra Fluoride). And with a fixed replacement rhythm of 1,500 litres or six months per element, that will be familiar to you as well. And when you look at the price, the Coldstream FTO PLUS filter, with direct fluoride reduction, is also quite a bit cheaper than the British Berkefeld variant. A nice bonus, then! The manuals for the switch can be found in [the shop's library](https://www.alternatievemiddelen.nl/handleidingen-coldstream-fto-plus-filters-en-pure-filters-waterfilters/?utm_source=helder&utm_medium=companion&utm_campaign=poc); if you cannot work it out, Tom will simply take a look along with you via WhatsApp.\n\n> **In short.** British Berkefeld stopped using dealers, your system does not have to go anywhere. The Coldstream FTO PLUS fits in it, filters more (including direct fluoride), needs no priming and is simply in stock at Alternatievemiddelen.nl, who know which water filter you have.",
"product_ids": [
81536,
81457,
81537,
81456
],
"brand": null,
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "Which water filter should you buy? Berkey, BOROUX or Pure Filters",
"titles": {
"en": "Which water filter should you buy? Berkey, BOROUX or Pure Filters",
"de": "Welchen Wasserfilter sollten Sie kaufen? Berkey, BOROUX oder Pure Filters",
"nl": "Welke waterfilter kopen? Berkey, BOROUX of Pure Filters"
},
"kicker": "Guide · buying a water filter",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/welk-waterfilter-kopen/",
"de": "https://waterfilterhouse.com/de/ratgeber/welk-waterfilter-kopen/",
"nl": "https://waterfilterhouse.com/nl/uitleg/welk-waterfilter-kopen/"
},
"url": "https://waterfilterhouse.com/en/guides/welk-waterfilter-kopen/",
"intro": "The three quality brands that remain after all the changes in the water filter world, honestly side by side: capacity, elements, cost per year and who they suit. With current stock.",
"body_markdown": "## First the honest question: what for?\n\nDutch tap water meets the statutory standards. You buy a gravity filter as an extra step on top of that basic quality, for the taste, or because you want to decide for yourself what is still in your water. If that is your starting point, these are the three quality brands that matter today.\n\n## The three brands\n\n**Berkey** water filters are currently still available with original Black Berkey filter elements. In the near future this is expected to change, with Berkey water filters being supplied as standard with Phoenix Gravity New Millennium Edition elements. That changes the replacement interval of the filters and also makes them less powerful. So at the moment they can still be had in their original state. The Go (1 litre), Travel (5.6 litres), Big (8.5 litres), Royal (12.3 litres), Imperial (17 litres) and Crown (22.7 litres) offer a wide range, so there is a fit for every situation.\n\n**BOROUX** with the BOROUX Foundation filters is the continuation of the original black carbon elements: the same basic formula as the Black Berkey filters, with a recommended service life of a maximum of three years per set (based on Dutch tap water and average use. **Please note!** This is a practical guideline and not a fixed replacement period). The Compact (6.8 litres) fits in most kitchens; the large Legacy (11.4 litres) is made for families, and both are also available in white, black and sage green. Filtering fluoride requires additional ProActive filter elements. Elements have to be primed (Alternatievemiddelen.nl will do it for you if you wish, but an automatic priming pump is much easier and a real recommendation).\n\n**Pure Filters** builds on the ceramic Coldstream FTO PLUS element from England: no priming, fluoride reduction included, replace every six months or 1,500 litres. The Voyager (6 litres), Home (9 litres) and Family (12 litres) cover every household; getting started is cheaper, but the elements are changed more often.\n\nIn short: Berkey (for the moment) and BOROUX win on service life, Berkey on its wide range, BOROUX on colour options, Pure Filters on convenience and entry price. For all three: the test reports per substance are simply online.\n\n## And British Berkefeld, ProOne and replacements for Berkey?\n\nThe familiar line-up of a few years ago no longer exists as such. [British Berkefeld stopped selling through dealers](/uitleg/british-berkefeld-alternatief/), [ProOne disappeared after a takeover](/uitleg/proone-alternatief-coldstream/) and [Black Berkey elements can no longer be supplied individually](/uitleg/black-berkey-alternatief/). Existing systems from these brands do, however, simply carry on running on today's elements (BOROUX Foundation and Coldstream FTO PLUS); the links above explain how, brand by brand.\n\n## What to count on\n\nLook at three figures: the purchase of the water filter, the cost of elements per year, and the capacity: allow roughly two litres of chamber capacity per household member as a daily buffer. And choose on the basis of test reports per substance, not promises. Unsure between the sizes? The [selection guide](/keuzehulp/) works it out for you.",
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81334,
81375,
81338,
81374,
81325,
81342,
81515,
81463,
81542,
81489,
81525,
81464,
81545,
81490,
81457,
81537,
81456
],
"brand": null,
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:47:35Z"
},
{
"title": "How does a gravity filter work (without a tap connection)?",
"titles": {
"en": "How does a gravity filter work (without a tap connection)?",
"de": "Wie funktioniert ein Schwerkraftfilter (ohne Wasseranschluss)?",
"nl": "Hoe werkt een zwaartekrachtfilter (zonder kraanaansluiting)?"
},
"kicker": "Guide · water filter without connection",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/hoe-werkt-een-zwaartekrachtfilter/",
"de": "https://waterfilterhouse.com/de/ratgeber/hoe-werkt-een-zwaartekrachtfilter/",
"nl": "https://waterfilterhouse.com/nl/uitleg/hoe-werkt-een-zwaartekrachtfilter/"
},
"url": "https://waterfilterhouse.com/en/guides/hoe-werkt-een-zwaartekrachtfilter/",
"intro": "No plumber, no electricity: a gravity filter runs on gravity. This is how the system is put together and what you can expect from it.",
"body_markdown": "## Gravity does the work\n\nA gravity filter (also known as a worktop filter) is two chambers stacked on top of each other. You pour tap water into the upper chamber, which holds the filters, gravity pushes it through the filter elements, and at the bottom you draw off the filtered water through the tap. No connection to the water mains, no electricity, no plumber: put it down and pour.\n\n## The element is the filter\n\nEverything the system does happens in the elements: compressed carbon or ceramic that the water seeps through. How much an element holds back differs per brand and per substance; serious manufacturers supply test reports with reduction percentages per substance. More filter elements in the same housing mainly means: faster filtering, not better filtering.\n\n## Priming: the step everyone forgets\n\nNew black carbon elements (from Berkey and BOROUX, for example) first have to be 'primed': flushed under light pressure until the pores are full of water instead of air. If you skip that, the system runs painfully slowly or not at all and you think the filter is broken. Tools, instructions and a manual are of course included; allow a maximum of five minutes per element. Handy optional accessories can also be ordered with it, and we really recommend them: BOROUX Automatic Filter Primer Pump (electric). With white ceramic elements (such as Coldstream FTO PLUS) priming is not necessary; it does that itself (by soaking itself full). Do bear in mind that at first it can take up to 24 hours before any water runs through. \n\n## What you can expect\n\nCount on a throughput of a few litres per hour per filter set: as an example, you fill the upper chamber and an hour later there is filtered water. That is why a household usually has enough with a water filter of 6 to 12 litres: the system works while you do something else. With black carbon elements (from Berkey and BOROUX, for example) the following applies: the better the priming has worked, the better they flow. This can therefore differ per filter and is entirely normal. With white ceramic elements (such as Coldstream FTO PLUS) the speed is constant and somewhat slower than with black carbon filters.",
"product_ids": [
81461,
81506,
81376,
81536
],
"brand": null,
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "How often should you replace a filter element?",
"titles": {
"en": "How often should you replace a filter element?",
"de": "Wie oft sollten Sie ein Filterelement austauschen?",
"nl": "Hoe vaak moet je een filterelement vervangen?"
},
"kicker": "Guide · replacing a filter element",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/filterelement-vervangen/",
"de": "https://waterfilterhouse.com/de/ratgeber/filterelement-vervangen/",
"nl": "https://waterfilterhouse.com/nl/uitleg/filterelement-vervangen/"
},
"url": "https://waterfilterhouse.com/en/guides/filterelement-vervangen/",
"intro": "An explanation of service life, advice per brand and per filter element, how you can tell whether replacement is needed and a simple way to keep track of it.",
"body_markdown": "## There is no universal replacement period\n\nThe actual service life of the filters depends on several factors, such as: the quality of the water, the contaminants present and their concentrations, daily water consumption, the substances you specifically want to filter and the construction of the filter. Manufacturers often give a general replacement recommendation, based on a broad group of users and water qualities. In practice, the optimal replacement period can differ from user to user.\nBased on experience with Dutch tap water, Alternatievemiddelen.nl currently advises as follows (with average use and the use of tap water): **Black Berkey filters**: replace the filters after a **maximum** of three years, **BOROUX Foundation Black filters**: replace the filters after a **maximum** of three years, **Phoenix Gravity New Millennium Edition filters**: replace the filters after a **maximum** of one year, **Coldstream FTO PLUS filters**: replace the filters after a **maximum** of 6 months, **Berkey PF-2 fluoride filters**: replace the filters after a **maximum** of one year and **BOROUX ProActive fluoride filters**: replace the filters after a **maximum** of one year. This is a practical guideline and not a fixed replacement period. If you use water with higher concentrations of certain contaminants (for example water from other sources), have a high water consumption or want to retain maximum certainty for specific substances, you are better off replacing the filters sooner. If you want to determine exactly when replacement is needed, only periodic analysis of the filtered water can give a definitive answer.\n**Please note**: the test results and maximum capacities differ per contaminant. Always consult the most up-to-date information and test results of each brand for this.\n\n## How to tell it is time sooner\n\nThe first signal is slowness: the upper chamber noticeably takes longer to empty. With the black filters (Black Berkey, BOROUX Foundation and Phoenix Gravity New Millennium Edition), priming again (saturating with water) should make them flow through properly again. If that does not help, a clean (followed by priming again) should provide a better flow. With ceramic elements (Coldstream FTO PLUS and ProOne) you only need to clean them, and that should raise the speed again somewhat. You clean by rinsing the filters briefly under a cold tap and then lightly scouring them with a scouring sponge. If none of this helps, it is a signal that replacement is due. Of course, also always keep an eye on the taste of the filtered water, because that is naturally the best indication of whether replacement is needed. \n\n## The handiest habit\n\nLink replacement to a fixed moment, for example spring, and write the date of installation with a waterproof marker on the box of the filter element. A note in your diary is of course handy too, and who does not have a phone these days. There is no more admin than that. Below you can see all the filters (with their current stock status) that are currently available.",
"product_ids": [
81461,
81483,
81536,
81377,
81467,
81468
],
"brand": null,
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:47:35Z"
},
{
"title": "What does a shower filter do and when does it make sense?",
"titles": {
"en": "What does a shower filter do and when does it make sense?",
"de": "Was bewirkt ein Duschfilter und wann ist er sinnvoll?",
"nl": "Wat doet een douchefilter en wanneer is het zinvol?"
},
"kicker": "Guide · shower filter",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/douchefilter-zinvol/",
"de": "https://waterfilterhouse.com/de/ratgeber/douchefilter-zinvol/",
"nl": "https://waterfilterhouse.com/nl/uitleg/douchefilter-zinvol/"
},
"url": "https://waterfilterhouse.com/en/guides/douchefilter-zinvol/",
"intro": "What a shower filter does and does not do, how often the cartridge needs replacing and which filter is in stock.",
"body_markdown": "## What a shower filter does\n\nYou screw a shower filter on between the tap and the shower hose or between a connecting rod and the shower head. The filter reduces, among other things, chlorine (by-)products and any other chemicals in the shower water. Inside, a mixture of a high-quality copper-zinc alloy and calcium sulphite works to neutralise chemicals before they reach your skin and hair. These ingredients are also known for reducing limescale, but the brand makes no claim about this. The result is cleaner, softer water that feels noticeably softer from the very first shower. It is a small intervention with a small price, so trying it is the quickest way to find out for your situation.\n\n## What a shower filter does not do\n\nThe water you shower with can contain as many contaminants as unfiltered drinking water. You do not use a shower filter as a drinking water filter. A shower filter focuses on a few contaminants, which makes showering more pleasant and softer. Chemicals in your shower water can, after all, cause dry hair and dry skin. If you want to reduce a larger number of contaminants in order to use the water for drinking, you need an ordinary (gravity) water filter, not a shower filter. \n\n## Maintenance\n\nThe cartridge is saturated after about half a year and you replace it in a minute, without tools. If you shower very often during the day, replacement will be closer to 3 months. Set a reminder for it in your calendar, or write it on the shower filter with a waterproof marker.",
"product_ids": [
81502
],
"brand": null,
"created": "2026-10-16T08:42:18Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "Cleaning and maintaining a water filter in 5 steps",
"titles": {
"en": "Cleaning and maintaining a water filter in 5 steps",
"de": "Wasserfilter reinigen und warten in 5 Schritten",
"nl": "Waterfilter schoonmaken en onderhouden in 5 stappen"
},
"kicker": "Guide · cleaning a water filter",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/waterfilter-onderhoud/",
"de": "https://waterfilterhouse.com/de/ratgeber/waterfilter-onderhoud/",
"nl": "https://waterfilterhouse.com/nl/uitleg/waterfilter-onderhoud/"
},
"url": "https://waterfilterhouse.com/en/guides/waterfilter-onderhoud/",
"intro": "A stainless steel gravity filter lasts for decades if you treat it well. The maintenance rhythm, the cleaning steps and the parts that wear out.",
"body_markdown": "## The rhythm\n\nA stainless steel gravity filter lasts for decades; the maintenance is light but needs a rhythm. Weekly: nothing. Monthly: rinse the chambers. Every 3 to 6 months: the big service (see below), a quarter of an hour's work.\n\n## The big service in 5 steps\n\n1. Drain the system and take the chambers apart.\n2. Wash both chambers and the small parts with warm water and a mild washing-up liquid; no abrasives on stainless steel, no dishwasher. Always rinse thoroughly.\n3. **Cleaning the filter elements**: **A. Black carbon elements (Black Berkey or BOROUX Foundation)**: rinse under a cold tap and lightly scour with a scouring sponge. Then prime again (saturate with water), see also the manual. **B. White ceramic elements (Coldstream FTO PLUS)**: scrub the outer wall clean under running cold water with a soft brush or scouring sponge until the light colour returns (this may also be done monthly if you wish).\n4. Limescale in the chambers? A splash of white vinegar in warm water dissolves it; leave it to stand for a while and then rinse thoroughly.\n5. Check the rubbers and the tap for wear, put everything back together hand-tight (so do not overdo the tightening) and fill the upper chamber again.\n\n## The parts that wear out\n\nIt is not the stainless steel but the small parts that determine the service life: the tap, the rubber rings and the blocking plugs. They cost from a few euros to a few tens of euros and are available separately from Alternatievemiddelen.nl. [Of course the filters also have to be replaced at some point](/uitleg/filterelement-vervangen/). If you are leaving on holiday and taking the water filter with you or transporting it, secure the filters in the upper chamber well or take them out for the journey. This prevents damage and therefore disappointment during the trip.",
"product_ids": [
81553,
81419,
81422,
81421,
81550,
81400,
81429,
81393,
81547
],
"brand": null,
"created": "2026-10-16T08:42:19Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "Filtering water while travelling and camping",
"titles": {
"en": "Filtering water while travelling and camping",
"de": "Wasser filtern auf Reisen und auf dem Campingplatz",
"nl": "Water filteren op reis en op de camping"
},
"kicker": "Guide · water filter for travel",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/waterfilter-op-reis/",
"de": "https://waterfilterhouse.com/de/ratgeber/waterfilter-op-reis/",
"nl": "https://waterfilterhouse.com/nl/uitleg/waterfilter-op-reis/"
},
"url": "https://waterfilterhouse.com/en/guides/waterfilter-op-reis/",
"intro": "From a drinking bottle with a filter element to a compact travel system: this is how you drink water you can rely on while on the move.",
"body_markdown": "## The bottle that filters\n\nFor on the move, at the campsite or simply in your gym bag, a drinking bottle with a built-in filter element is the lightest solution. You fill it at any tap and the element filters while you drink. You replace the filter element in the bottle separately; the bottle itself lasts for years.\n\n## The system that travels with you\n\nIf you travel by camper van, stay at a seasonal pitch or have a holiday home, you take a compact gravity system with you. The smallest water filters, of about 6 litres, work anywhere: no connection, no electricity. Tip: if you are going to be driving with it, secure the filters in the upper chamber well or take them out for the journey. This prevents damage and therefore disappointment during your holiday. \n\n## Backpacking and hitting the road with a rucksack\n\nIf you are travelling with just a rucksack, space and weight are an important consideration. Even so, a water filter is a must-have for your rucksack. The Go Berkey Kit is ideal for this. A stainless steel drinking cup of about 1 litre, including a small upper chamber with an original Black Berkey filter in it. It slides together compactly and is not heavy either. Enjoy pure water everywhere.\n\n## An honest limit\n\nThese filters are made for tap water and clear mains water of varying taste and composition, such as you come across when travelling. For surface water or springs whose safety you do not know, the manufacturer's specifications and limitations per element apply: read them before you leave, not afterwards.",
"product_ids": [
81344,
81375,
81515,
81463,
81542,
81489,
81457,
81334
],
"brand": null,
"created": "2026-10-16T08:42:16Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "Is filtering tap water necessary in the Netherlands?",
"titles": {
"en": "Is filtering tap water necessary in the Netherlands?",
"de": "Ist das Filtern von Leitungswasser in den Niederlanden nötig?",
"nl": "Is kraanwater filteren nodig in Nederland?"
},
"kicker": "Guide · filtering tap water",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/kraanwater-filteren-nodig/",
"de": "https://waterfilterhouse.com/de/ratgeber/kraanwater-filteren-nodig/",
"nl": "https://waterfilterhouse.com/nl/uitleg/kraanwater-filteren-nodig/"
},
"url": "https://waterfilterhouse.com/en/guides/kraanwater-filteren-nodig/",
"intro": "The honest answer: no, it is not necessary. Why people do it anyway, what the measurements say and when a filter adds something.",
"body_markdown": "## The short answer: no\n\nDutch tap water is among the best in the world and meets the statutory standards. The Dutch public health institute RIVM and the water companies say it without beating about the bush: “a home filter is not necessary in the Netherlands”. A shop that sells water filters and therefore opens with that answer is not trying to pull the wool over your eyes. That is precisely why it is stated here.\n\n## Why people filter anyway\n\nThe honest reasons from practice: an improvement in taste (contaminants and therefore taste differ per region), the wish to have an extra buffer of one's own on top of the standards set by the government, old internal pipework in the house, etc. or simply: staying in control yourself. The discussion about substances such as PFAS, microplastics and the increase in medicine residues and pesticides also shows that standards are not an end point but a snapshot; those who do not want to wait for that, add their own filtering.\n\n## If you do it, make it measurable\n\nChoose a water filter whose manufacturer shows per substance what it does, in test reports with reduction percentages and a test standard alongside. Avoid anything that sells with fear or with promises without figures. And work out the cost per year in advance: a filter that you do not maintain or replace can be worse than no filter.",
"product_ids": [],
"brand": null,
"created": "2026-10-16T08:42:16Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "Water filter emergency kit: how to make your water supply safe",
"titles": {
"en": "Water filter emergency kit: how to make your water supply safe",
"de": "Wasserfilter-Notfallpaket: So sichern Sie Ihre Wasserversorgung",
"nl": "Waterfilter noodpakket: zo stel je je watervoorraad veilig"
},
"kicker": "Guide · water filter emergency kit",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/waterfilter-noodpakket/",
"de": "https://waterfilterhouse.com/de/ratgeber/waterfilter-noodpakket/",
"nl": "https://waterfilterhouse.com/nl/uitleg/waterfilter-noodpakket/"
},
"url": "https://waterfilterhouse.com/en/guides/waterfilter-noodpakket/",
"intro": "The government advises an emergency supply for at least three days. A water filter emergency kit makes sure you have safe drinking water even during a power cut or contamination. In this article you can read which components you need and how to put it together easily.",
"body_markdown": "## Why a water filter emergency kit?\n\nThe government advises households to prepare for at least three days of emergencies such as power cuts, flooding or contamination of the drinking water supply. Water is the most critical item here. A major advantage of a gravity filter over bottled water alone is that you do not have to keep giving up endless storage space for your supply. You simply filter tap water, rainwater or surface water that you have collected safely.\n\n## What belongs in a water filter emergency kit?\n\nA complete emergency kit consists of a few fixed components that you can put together yourself. The basis is a water filter that works by gravity. This system needs no power and works entirely mechanically. You pour the water into the upper tank and it filters by itself into the lower tank.\n\nBesides the water filter itself, you need extra filter elements. In an emergency the filter capacity can run out quickly, especially if you also want to boil water or use it for more purposes. Always keep at least one set of spare filter elements. For specific contaminants such as fluoride or arsenic you can add supplementary elements. In emergencies we advise using these.\n\nA maintenance and cleaning kit is indispensable. After longer storage or when using cloudy water, you need to clean the element regularly. A special filter brush or scouring sponge will keep your element's service life at its maximum. Having small spare parts on hand as well means you can always carry on.\n\nFinally, you need clean ways of collecting the water. Glass drinking bottles or a carafe are ideal for storing the filtered water straight away. Avoid plastic bottles that have been standing in the cupboard for a long time, because these can, among other things, dry out or absorb odours.\n\n## How do you put the emergency kit together?\n\nChoose a system that suits the size of your household. For one or two people a compact model is enough. For families, choose a larger version. Do you have a Black Berkey system? Then BOROUX is the successor with exactly the same filter formula. Alternatievemiddelen.nl is the only dealer in Europe for this brand name. The switch is seamless and the performance stays the same.\n\nIf you previously had a ProOne system or a British Berkefeld filter at home, be aware that these brands have ended their dealer activities. The existing systems simply carry on running on the very powerful Coldstream FTO PLUS element. This element comes from an English factory and is the standard replacement for both brands. Of course, we supply this element too.\n\n## Maintenance and storage\n\nStore your emergency kit in a cool, dry place. Check every year whether the rubber seals are still supple and whether the filter elements are undamaged. A Berkey or BOROUX element that has not been used for a longer time is best reactivated (primed) before you put it into use. The priming button (brown rubber ring), PrimeRite (blue spout), the manual primer or the automatic primer will help you with this. For more explanation about working with a gravity filter, we refer you to [how does a gravity filter work](/uitleg/hoe-werkt-een-zwaartekrachtfilter/).\n\n## Test reports and performance\n\nIndependent test reports show that the ceramic and carbon elements in these systems significantly reduce, among other things, heavy metals, pesticides, bacteria, medicine residues, microplastics, viruses and PFAS (from 90 to 99.9%). The exact percentages vary per substance and element type. Always consult the manufacturer's current certificates for the specific measurement results.\n\n> **In short.** A water filter emergency kit consists of a gravity filter, spare elements, a cleaning kit and ways of collecting water. It works without power, saves space compared with a stock of bottles and can be used straight away in a power cut or contamination. Check your supplies every year and keep the components dry.",
"product_ids": [
81461,
81536,
81515,
81525,
81375,
81338,
81374,
81457,
81537,
81456,
81553
],
"brand": null,
"created": "2026-10-16T08:42:16Z",
"updated": "2026-10-16T10:46:10Z"
},
{
"title": "Making rainwater drinkable: how to filter it safely",
"titles": {
"en": "Making rainwater drinkable: how to filter it safely",
"de": "Regenwasser trinkbar machen: So filtern Sie es sicher",
"nl": "Regenwater drinkbaar maken: zo filter je het veilig"
},
"kicker": "Guide · making rainwater drinkable",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/regenwater-drinkbaar-maken/",
"de": "https://waterfilterhouse.com/de/ratgeber/regenwater-drinkbaar-maken/",
"nl": "https://waterfilterhouse.com/nl/uitleg/regenwater-drinkbaar-maken/"
},
"url": "https://waterfilterhouse.com/en/guides/regenwater-drinkbaar-maken/",
"intro": "Collecting rainwater is sustainable, but not immediately suitable for consumption. Find out which steps and filter elements are needed to make it safe for drinking, with measurable reduction percentages and practical tips for off-grid living.",
"body_markdown": "## Is rainwater directly drinkable?\n\nWater that falls from the sky is clean in principle. As soon as it touches your roof, however, it picks up dust, bird droppings, leaves and residues of roofing material. That makes it unsuitable for direct drinking. For tiny houses, off-grid living or emergencies, controlled purification is therefore essential.\n\n## Step one: coarse filtering and first flush\n\nAlways start with a pre-filter or strainer. This catches leaves, twigs and coarse particles before the water enters your storage tank or filter system. Many roofs have grilles in their gutters that hold back such coarse parts. Tip: afterwards, let the water pass through a piece of old textile to hold back smaller particles. Or use another pre-filter. This protects your filter elements against clogging and extends their service life considerably.\n\n## Step two: thorough cleaning with a gravity filter\n\nRainwater can contain all kinds of contaminants, including traces of air pollution, such as PFAS, pesticides or heavy metals. Preferably use a gravity filter. These work without power and slowly press the water through a porous element. A good gravity filter in fact already captures these contaminants completely. In independent test reports, these elements often show reductions of between 90 and 99 per cent for specific contaminants, depending on the concentration and flow rate. Always check the element's specific test report for the exact reduction percentages per substance. And it is definitely advisable to use additional fluoride filters with water from sources other than tap water.\n\nIn most brands of gravity water filter systems the same filter elements can be fitted (so as far as filters are concerned, you are brand-independent in an existing gravity water filter). BOROUX is the successor to Berkey with the same formula for the filter elements, and Alternatievemiddelen.nl is the only dealer in Europe. The famous ProOne G2.0 element is also really called Coldstream FTO PLUS and comes from an English factory; Alternatievemiddelen.nl supplies it. As an example: British Berkefeld stopped selling through dealers, but existing systems simply carry on running on Coldstream FTO PLUS. These elements are extremely well suited to this step of rainwater purification.\n\n## Practical tips for storage and maintenance\n\n- Preferably use dark, closed tanks to prevent algae growth.\n- Clean your roof gutters at least twice a year.\n- Rinse your filter elements regularly according to the instructions to maintain the flow rate.\n- Replace elements in good time; a clogged or aged filter no longer works reliably.\n\n> **In short.** Rainwater is not directly drinkable because of contamination from the roof. A safe chain consists of coarse pre-filtering, then reduction via a gravity filter of, among other things, PFAS, pesticides, heavy metals and other contaminants. Certified elements show reductions of 90 to 99.9999% in public test reports for many commonly occurring contaminants.",
"product_ids": [
81536,
81461,
81467,
81468,
81377
],
"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:47:35Z"
},
{
"title": "Water filter or water softener? What is the difference?",
"titles": {
"en": "Water filter or water softener? What is the difference?",
"de": "Wasserfilter oder Wasserenthärter? Was ist der Unterschied?",
"nl": "Waterfilter of waterontharder? Wat is het verschil?"
},
"kicker": "Guide · water filter or water softener",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/waterfilter-of-waterontharder/",
"de": "https://waterfilterhouse.com/de/ratgeber/waterfilter-of-waterontharder/",
"nl": "https://waterfilterhouse.com/nl/uitleg/waterfilter-of-waterontharder/"
},
"url": "https://waterfilterhouse.com/en/guides/waterfilter-of-waterontharder/",
"intro": "You often hear the terms used interchangeably, but they solve two different problems. A water filter purifies your drinking water of contaminants, while a water softener removes limescale from the mains water to prevent mineral deposits in pipes and appliances. Read here how to choose what suits your situation.",
"body_markdown": "## What does a water filter do?\n\nA water filter is intended for your drinking water. It removes substances that affect the taste, smell or quality of the water, such as chlorine, lead, pesticides, medicine residues, microplastics and PFAS. How well a filter works depends on the type of filter element and its certification. Reliable systems have their performance tested against public standards such as NSF/ANSI 42, 53 and 401. These test reports state the reduction percentages per substance. A good gravity filter, for example, removes more than 99 per cent of chlorine and more than 95 per cent of lead. For PFAS, reductions of more than 99 per cent are often achieved. You will always find the exact figures in the manufacturer's accompanying test report.\n\n## What does a water softener do?\n\nA water softener targets hard mains water. Hard water contains a lot of calcium and magnesium. These minerals are harmless to your health and even essential for your body, but they do form limescale deposits in pipes, heating elements, washing machines and shower heads. Most water softeners work with an ion exchanger: calcium and magnesium ions are replaced by sodium ions (salts). This makes the water softer, but the composition of your drinking water, as far as contaminants are concerned, does not change. A water softener therefore does not improve the taste or the purity of your drinking water. It is a system for the whole home or for specific places such as the washing machine and the shower.\n\n## Limescale or contaminants? Choose based on your question\n\nThe choice depends on what you want to achieve. Do you want better water in terms of taste and health, and therefore protection against contaminants from the drinking water network? Then you choose a water filter. Do you suffer from limescale on your tap, in the shower or on your clothes after washing? Then a water softener may be the right step. Many households sometimes combine both systems: a softener for the whole house and a gravity filter for the drinking water. Note: if the water softener works with sodium ions (salts), this can affect the filter elements in your gravity water filter. These salts can clump together and clog the filter element. The flow is then reduced or stops altogether. As a result you have to replace the filter elements early. Some water softeners do this more than others. TIP: You can often draw off water before the water softener; use this water for the water filter.\n\n## Gravity filter or tap filter?\n\nIf you choose a water filter, there are various types. A gravity filter works without power or water pressure. The water drips through the filter element by itself and collects in a lower container. This system is ideal if you want to be flexible or do not want a connection to the tap (a connection to a tap often also gives lower filter performance). For anyone looking for a successor to the original Berkey system: BOROUX uses the same formula and Alternatievemiddelen.nl is the only dealer of this brand in Europe. And note that the famous ProOne G2.0 filter element is really called Coldstream FTO PLUS and comes from an English factory; Alternatievemiddelen.nl supplies this element too. British Berkefeld stopped selling through dealers, but existing systems simply carry on running on Coldstream FTO PLUS. Both brands work on the same gravity principle and supply certified filter elements. And you can fit them in almost all existing gravity water filters, including those of other brands.\n\n> **In short.** A water filter purifies your drinking water of contaminants such as chlorine, lead, microplastics and PFAS, with reduction percentages that are stated in public test reports. A water softener removes limescale from the mains water to protect appliances, but changes nothing about the quality of the drinking water. Choose based on your question: purifying or preventing scale build-up. For drinking water, a gravity filter is often the most practical and flexible solution.",
"product_ids": [
81515,
81525,
81375,
81338,
81374,
81457,
81537,
81456,
81461,
81536
],
"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "Shower filter without ProOne: what now?",
"titles": {
"en": "Shower filter without ProOne: what now?",
"de": "Duschfilter ohne ProOne: Was nun?",
"nl": "Douchefilter zonder ProOne: wat nu wel?"
},
"kicker": "Guide · shower filter without ProOne",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/douchefilter-zonder-proone/",
"de": "https://waterfilterhouse.com/de/ratgeber/douchefilter-zonder-proone/",
"nl": "https://waterfilterhouse.com/nl/uitleg/douchefilter-zonder-proone/"
},
"url": "https://waterfilterhouse.com/en/guides/douchefilter-zonder-proone/",
"intro": "The ProOne ProMax line is sold out. This article explains why that is, what the alternatives are and why switching to the BOROUX shower filter is often the most logical step. You will read how a shower filter works, what you do and do not achieve with it, and what to look out for when buying.",
"body_markdown": "## Why is the ProOne ProMax line sold out?\n\nThe ProOne ProMax line has not been in stock for quite some time. Production and distribution of these specific shower filters have been discontinued, which means Alternatievemiddelen.nl can no longer receive new stock. This is because the ProOne brand has been taken over, and the new owner has stopped producing shower filters and has also stopped selling through European dealers. If you have bought or used a ProOne shower filter in the past, you run into the same challenges as with the ProOne water filters for drinking water.\n\n## What does a shower filter actually do?\n\nA shower filter sits between the water pipe and your shower head (possibly with the hose in between, of course). The water flows through a filter cartridge that holds back impurities before it touches your skin and hair. Independent test reports generally show a chlorine reduction of 90 to 99 per cent, depending on the flow rate and the specific filter technology. Limescale (calcium and magnesium) is also partly bound, which lowers the water hardness locally. This does not mean the filter softens your tap water, but it can help to reduce limescale deposits on your shower head and pipes.\n\nA shower filter does not solve bacteriological problems and is not a substitute for a drinking water filter. It is purely an aid to improve the water quality in the shower. Read more about how it works in general and where it is used in [what does a shower filter do and when does it make sense?](/uitleg/douchefilter-zinvol/).\n\n## Switching to BOROUX\n\nFor some time now, Alternatievemiddelen.nl has supplied the BOROUX shower filter as the direct successor to the ProOne ProMax line. BOROUX uses the same filtration technology and builds on the knowledge gained with its gravity filter systems. Alternatievemiddelen.nl is the only BOROUX dealer in Europe, which ensures immediate availability and full warranty. The shower filter is easy to replace and fits the standard shower connections found in most households.\n\nTechnically, the switch is smooth. You can connect the BOROUX shower filter effortlessly to the mixer tap in the shower (followed by the hose) or directly between a connection from the wall or ceiling and the shower head (for example with a rain shower). The shower filter lasts three to six months on average, depending on your water hardness and shower use. Replacing it is simple: unscrew the shower filter and screw on the new one.\n\n## What should you look out for when buying?\n\nNot every shower filter delivers the same results. Pay attention to the following points before you choose:\n\n- Check the connection size. Most Dutch shower hoses have a standard size of 1/2 inch. Make sure the shower filter and the couplings fit this.\n- Ask for the test reports. Honest suppliers share public measurement results from independent laboratories. Look for specific reduction figures for chlorine, lead and other contaminants.\n- Take the flow rate into account. A filter that is too strong can noticeably lower the water pressure in the shower. Choose a cartridge that is matched to standard household showers.\n- Plan the maintenance. Shower filters become saturated. Replacing a shower filter prevents impurities from being released into the water again.\n\n> **In short.** The ProOne ProMax line is sold out because production has been discontinued. The BOROUX shower filter is the direct successor with the same filtration technology and is supplied exclusively by Alternatievemiddelen.nl in Europe. A shower filter lowers chlorine and binds limescale, but does not solve bacterial problems. Choose based on public test reports, standard connection sizes and a clear maintenance schedule.\n\nAre you also looking for a water filter for your drinking water and want to know which water filter best suits your situation? Then take a look at [which water filter should you buy?](/uitleg/welk-waterfilter-kopen/).",
"product_ids": [
81502
],
"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:43:46Z"
},
{
"title": "A drinking bottle with a filter for on the go: what works and what is important to know?",
"titles": {
"en": "A drinking bottle with a filter for on the go: what works and what is important to know?",
"de": "Eine Trinkflasche mit Filter für unterwegs: Was funktioniert und was ist wichtig zu wissen?",
"nl": "Een drinkfles met filter voor onderweg: wat werkt en wat is belangrijk om te weten?"
},
"kicker": "Guide · drinking bottle with filter for on the go",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/drinkfles-met-filter-voor-onderweg/",
"de": "https://waterfilterhouse.com/de/ratgeber/drinkfles-met-filter-voor-onderweg/",
"nl": "https://waterfilterhouse.com/nl/uitleg/drinkfles-met-filter-voor-onderweg/"
},
"url": "https://waterfilterhouse.com/en/guides/drinkfles-met-filter-voor-onderweg/",
"intro": "When travelling, exercising, camping or cycling, you often want to drink fresh tap water. A drinking bottle with a filter keeps you hydrated and limits unwanted substances. We explain what matters and what is ideal.",
"body_markdown": "## Why filter on the go?\nTap water in the Netherlands is safe according to government standards, but its quality differs by region and period. When travelling, exercising, camping or cycling, you sometimes end up in situations where you would like to purify the available water. A drinking bottle with a filter combines hydration with a built-in purification system. The biggest advantage is that you have safe drinking water straight away without plastic waste.\n\n## How does a drinking bottle with a filter work?\nMost reliable models use filters that are also used in larger water filters, but in a smaller size. This technology often works by gravity or by gently squeezing the bottle in combination with sucking. The filters apply microfiltration, in which the water has to pass through a micro-porous structure that holds back sediment and particles. This happens in combination with adsorption, in which certain substances are bound to the surface of the filter medium (e.g. heavy metals and other contaminants). \n\n## What does a filter element remove and what not?\nOf course this differs per brand and type of drinking bottle with a filter. Most reduce a wide range of unwanted substances in the water, including heavy metals, pesticides, organic chemicals, chlorine and chloramine, medicine residues and petroleum/fuel-related contaminants. For many of the substances tested you see reduction percentages of 99% to 99.9% in official test reports. Fluoride is usually not reduced, and often no claims are made about bacteria and viruses either. Bear in mind that filter capacity is limited, because it is a small version. As the element is used repeatedly, the flow rate drops and the degree of purification decreases. So replace the element in good time.\n\n## Practical use and maintenance\nA drinking bottle with a filter is ideal for day trips, sports activities, cycling holidays or camping. The capacity is usually between 500 and 750 millilitres. The filter element is replaceable and can often be cleaned by backflushing with clean cold water. The bottle itself with warm water and a little washing-up liquid. Preferably store the bottle empty and dry when you are not using it, so that no bacteria or mould can grow in the damp filter.\n\n## Which bottle should you choose?\nThe Sport Berkey drinking bottle uses the same filter element as the large Berkey water filters. The technology is proven and delivers a high degree of purification. The filter elements can be detached, as can other parts of this drinking bottle (think of the cap and straw). It is handy like a normal sports bottle, but do bear in mind that it is not an ordinary bottle. The water is purified instantly, so a combination of lightly squeezing and sucking on the straw is important for the best experience.\n\n> **In short.** A good drinking bottle with a filter uses roughly the same filters as large water filters. Among other things, it removes heavy metals, pesticides, organic chemicals, chlorine and chloramine, medicine residues and petroleum/fuel-related contaminants. Replace the element in good time and store the bottle dry. For on the go, a model with a replaceable element and a capacity of 500 to 750 ml is the most practical.",
"product_ids": [
81344,
81334
],
"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:46:10Z"
},
{
"title": "Does a water filter also remove good minerals?",
"titles": {
"en": "Does a water filter also remove good minerals?",
"de": "Entfernt ein Wasserfilter auch gute Mineralstoffe?",
"nl": "Haalt een waterfilter ook goede mineralen weg?"
},
"kicker": "Guide · water filter minerals",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/haalt-een-waterfilter-goede-mineralen-weg/",
"de": "https://waterfilterhouse.com/de/ratgeber/haalt-een-waterfilter-goede-mineralen-weg/",
"nl": "https://waterfilterhouse.com/nl/uitleg/haalt-een-waterfilter-goede-mineralen-weg/"
},
"url": "https://waterfilterhouse.com/en/guides/haalt-een-waterfilter-goede-mineralen-weg/",
"intro": "Many people fear that a water filter removes calcium and magnesium from tap water. That is not true for every water filter. A gravity filter in fact lets the good minerals through and removes only what really needs to go. A Reverse Osmosis water filter (RO system) does reduce these minerals, as well as contaminants. In this article you can read about the differences and what does and does not disappear from your water.",
"body_markdown": "## The short answer\nNo, for gravity water filters. Yes, for Reverse Osmosis (RO) systems. \n\n## How a gravity water filter works\nA gravity water filter, with ceramic and/or carbon-containing elements, does not remove good minerals such as calcium and magnesium from your tap water. The outer filter layer holds back only contaminants that are larger than the pores. Bacteria, turbidity and rust, for example, stay behind as a result. The activated carbon layer underneath works through adsorption. With this, the filter binds chlorine, odour and taste substances and other contaminants. Good minerals are dissolved ions. They are much smaller than the filter pores and have no chemical affinity with the carbon. They simply flow through.\n\n## How a Reverse Osmosis (RO) water filter works\nA Reverse Osmosis (RO) water filter works with a very fine membrane and removes a large part of the dissolved substances from the water. As a result, many unwanted substances can be greatly reduced, but at the same time naturally present minerals such as calcium and magnesium are also largely removed from the water.\n\n## What stays in your water\nCalcium and magnesium stay in the filtered water with a gravity water filter. These minerals give the water a lovely taste and are essential for your body, but people naturally get most of them from food such as vegetables, nuts, dairy and whole grains. A water filter of course focuses mainly on removing what you do not want in your water: e.g. chlorine, heavy metals, PFAS, traces of pesticides and microplastics. If you still want to add minerals, that is certainly no problem. The filters supplied by Alternatievemiddelen.nl are not designed to extract minerals. On the contrary, they make the water taste better by removing chlorine and other unwanted substances, while the natural mineral composition remains intact.\n\n> **In short.** A gravity filter does not remove calcium or magnesium. The filter pores and the carbon hold back only contaminants that are larger or that bind chemically. Good minerals flow through, and contaminants such as chlorine, heavy metals, pesticides, medicine residues, PFAS, microplastics and chemicals are reduced. The technology in Reverse Osmosis (RO) systems works differently, which means good minerals do disappear.",
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81461,
81536,
81375,
81338,
81374,
81515,
81525,
81457,
81537,
81456
],
"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:47:35Z"
},
{
"title": "What does a water filter test report contain?",
"titles": {
"en": "What does a water filter test report contain?",
"de": "Was steht in einem Testbericht zu einem Wasserfilter?",
"nl": "Wat staat er in een testrapport van een waterfilter?"
},
"kicker": "Explained · water filter test report",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/watstaaterein-testrapport/",
"de": "https://waterfilterhouse.com/de/ratgeber/watstaaterein-testrapport/",
"nl": "https://waterfilterhouse.com/nl/uitleg/watstaaterein-testrapport/"
},
"url": "https://waterfilterhouse.com/en/guides/watstaaterein-testrapport/",
"intro": "A good test report shows which substances were actually examined, how much of them was measured before and after filtration, and after how many litres of water the performance was established. Also look at who carried out the test and by which method. A laboratory test is not automatically the same as a certification.",
"body_markdown": "Claims such as *'removes PFAS'* or *'filters 99% of contaminants'* sound clear, but on their own they tell you very little.\n\nAfter all, which PFAS are we talking about? What was the concentration before filtration? How much was left after filtration? Was that measured only with a new filter, or also after hundreds or thousands of litres of water had passed through it?\n\nThat is why at Helder. we prefer to look at the **actual test report**.\n\n## What is a water filter test report?\nA laboratory report describes how a water filter performed under certain test conditions.\n\nDepending on the test, you will find things like:\n\n- the filter element or filter system tested;\n\n- the laboratory that carried out the test;\n\n- the test method or standard used;\n\n- the substances examined;\n\n- the concentration before filtration;\n\n- the concentration after filtration;\n\n- the calculated reduction percentage;\n\n- the amount of water filtered during the test;\n\n- various measuring points during the test.\n\nNot every report contains all of this information.\n\nThe more information is available about the test conditions, the better you can judge the result.\n\n## The key figures: influent and effluent\nIn laboratory reports you will often come across the terms **influent** and **effluent**.\n\n**Influent** is the water before filtration.\n\n**Effluent** is the water after it has passed through the filter.\n\nSuppose a laboratory measures 1.00 µg/L of a certain substance before filtration and 0.01 µg/L after filtration.\n\nThe calculated reduction is then:\n\n**99%**\n\nThat does not mean the substance has disappeared completely. The measured concentration has been reduced by 99%.\n\nThat is why we actually find the concentrations before and after filtration more informative than a big reduction percentage alone.\n\n## What does '<' mean in a test report?\nIn a laboratory report you might come across something like this:\n\n**<0.01 µg/L**\n\nThat does not automatically mean that exactly 0.01 µg/L was measured.\n\nA value such as <0.01 µg/L means that the concentration was below the limit stated by the laboratory. Which limit exactly is meant, for example a reporting limit or a detection limit, has to be clear from the laboratory report in question.\n\nOn the basis of such a result, the laboratory therefore cannot say exactly how much lower the actual concentration was.\n\nThat distinction is important.\n\n<0.01 µg/L therefore does not mean the same as 0.00 µg/L.\n\n## Why is the number of litres tested so important?\nSuppose two water filters show a reduction of 99% for the same substance.\n\nFor filter A, that result was measured after 10 litres had passed through the filter.\n\nFor filter B, the same reduction is still measured after 1,500 litres have been filtered.\n\nThe reduction percentage is the same, but the information the two tests give is clearly different.\n\nThat is why we don't only look at:\n\n**How much is reduced?**\n\nBut also at:\n\n**After how many litres was that measured?**\n\nSome reports use several measuring points. You can then see how the filter performs over the course of the test.\n\n## Test capacity is not automatically the service life\nThis is an important distinction.\n\nIf a filter was examined up to 1,500 litres in a laboratory test, that does not automatically mean the filter has to be replaced after exactly 1,500 litres.\n\nConversely, a service life stated by the manufacturer of, say, 5,000 litres does not automatically mean that every individual reduction claim was independently tested over the whole 5,000 litres.\n\nSo there are two different questions:\n\n**1. Up to what amount of water has the reduction of this specific substance been examined?**\n\n**2. What service life or replacement guideline does the manufacturer give for the filter element?**\n\nThese two figures can differ from each other.\n\nThe actual service life is also influenced by the composition of the water, the concentrations of various substances and the amount of water filtered each day.\n\n## What are NSF/ANSI 42, 53 and 401?\nWith water filters you regularly come across references to **NSF/ANSI 42, NSF/ANSI 53 and NSF/ANSI 401**.\n\nThese are standards with requirements and test methods for drinking water treatment systems.\n\nBroadly speaking:\n| Standard | What is it about, among other things? |\n|---|---|\n| NSF/ANSI 42 | Aesthetic effects and specific reduction claims, for example for chlorine, taste and odour |\n| NSF/ANSI 53 | Specific reduction claims for contaminants with a health-related effect, for example lead, certain VOCs and chromium |\n| NSF/ANSI 401 | Specific reduction claims for so-called *emerging compounds*, including certain medicines, pesticides, herbicides and other chemical substances |\n\nIt is important to know that a number such as **NSF/ANSI 53** does not in itself tell you which substances a specific filter reduces.\n\nYou always have to look at the **specific reduction claims for which the product has been tested or certified**.\n\nCertification for one claim within a standard does not automatically mean that a filter is certified for all possible claims within that standard.\n\n## Tested according to NSF/ANSI is not the same as certified\n\nThis is probably the most important distinction when reading water filter claims.\n\nA laboratory can examine a filter **according to a test method from an NSF/ANSI standard**.\n\nThat does not automatically mean that the complete product is also **NSF certified**.\n\nCertification assesses more than a single laboratory test. Depending on the certification, performance, materials and construction are assessed, among other things. Ongoing product certification also includes checks to verify that the product continues to meet the requirements.\n\nThat is why at Helder. we distinguish between wordings such as:\n\n**'tested according to the NSF/ANSI 401 test methodology'**\n\nand:\n\n**'certified to NSF/ANSI 401'**\n\nThese two statements do not mean the same thing.\n\n## Also look at who carried out the test\n\nA test report in PDF format is not in itself proof that a test was carried out independently.\n\nSo check who carried out the study.\n\nLook, for example, at:\n\n- the name of the laboratory;\n\n- the report number;\n\n- the test date;\n\n- the name of the product tested;\n\n- the test method used;\n\n- the measurement results;\n\n- any accreditation or certifying body.\n\nAlso check that the report actually relates to **the filter you want to buy**.\n\nA test of a particular filter material alone, for example, does not automatically tell you how a complete filter element performs.\n\n## Pay attention to the test concentration\n\nLaboratory tests are carried out under defined conditions. Certain concentrations of a substance may be deliberately added to the test water.\n\nThese concentrations can be considerably higher than the amounts normally found in Dutch tap water.\n\nThat does not make a laboratory test any less valuable. It is precisely because of the controlled conditions that performance can be examined reproducibly.\n\nIt does mean, though, that you should not translate a laboratory result one to one to the situation at home.\n\nA filter that reduces a substance by 99% during a test does not automatically guarantee that every household, with every water composition, will achieve exactly 99%.\n\n## Look per substance, not just at the filter\n\nA common mistake is to extend one good test result to all other substances.\n\nSuppose a filter reduces lead by 99%.\n\nOn its own, that tells you nothing about the reduction of:\n\n- PFAS;\n\n- medicine residues;\n\n- pesticides;\n\n- fluoride;\n\n- nitrates;\n\n- microplastics.\n\nEven within a single group there can be big differences.\n\nWith PFAS, for example, a filter may perform differently for PFOA than for PFBS. With medicine residues, the reduction of ibuprofen may differ from that of carbamazepine.\n\nThat is why the question:\n\n**'What percentage does this water filter filter out?'**\n\nis actually too general.\n\nA better question is:\n\n**'How well does this filter reduce this specific substance, under which test conditions and up to which tested capacity?'**\n\n## An example: 99% reduction doesn't tell you everything\n\nSuppose you see these two claims:\n| Filter | Reduction | Tested up to |\n|---|---:|---:|\n| Filter A | 99% | 50 litres |\n| Filter B | 98% | 1,500 litres |\n\nOn this basis you cannot simply conclude that filter A is better because 99% is higher than 98%.\n\nAmong other things, you need to know:\n\n- was the same substance tested?\n\n- was the starting concentration the same?\n\n- was the same test method used?\n\n- do the results come from independent laboratories?\n\n- is it a single measuring point or several?\n\n- under which conditions was it tested?\n\n**So never compare just the highest percentage.**\n\n## How do we assess test reports at Helder.?\n\nWhen we write on Helder. that a filter can reduce a certain substance, we try to go back to the original test data as far as possible.\n\nIn doing so, we look in particular at:\n\n**1. Which substance was actually tested?**\n\n**2. Which filter element was tested?**\n\n**3. Who carried out the test?**\n\n**4. According to which test method?**\n\n**5. What was the concentration before filtration?**\n\n**6. What was measured after filtration?**\n\n**7. Up to what amount of water was it tested?**\n\n**8. Is it a laboratory test or a certification?**\n\nThat is also the reason why in our articles on PFAS and medicine residues, for example, you see not only percentages but, wherever possible, the original measured values and test capacity too.\n\n## How do you compare two water filters fairly?\n\nWhen comparing two filters, preferably use the same checklist:\n| Question | Why is it important? |\n|---|---|\n| Was the same substance tested? | Otherwise you are comparing different performances |\n| Was the complete filter element tested? | A material test is not the same as a test of the end product |\n| What was the starting concentration? | Test conditions can differ greatly |\n| What was left after filtration? | Gives more information than a percentage alone |\n| After how many litres was it measured? | Shows up to which point performance has been examined |\n| Was the same test method used? | Makes the comparison more reliable |\n| Was it examined independently? | Gives you more to go on than a manufacturer's claim alone |\n| Is it tested or certified? | These are different levels of substantiation |\n\nWhen two manufacturers use different test methods, concentrations and capacities, you cannot simply set their reduction percentages directly against each other.\n\n## What does a test report not prove?\n\nEven a good laboratory report has its limits.\n\nA report proves how the filter tested performed **under the test conditions described**.\n\nIt does not automatically prove:\n\n- that exactly the same percentage is achieved at home;\n\n- that every substance is reduced;\n\n- that the performance continues to apply indefinitely;\n\n- that a filter stops working immediately after the tested capacity;\n\n- that a tested filter is automatically certified;\n\n- that every other filter with the same material performs the same.\n\nIt is precisely by stating these limitations clearly that a test report becomes much more useful.\n\n## Our most important tip\n\n**With a water filter, don't just read what the manufacturer says the filter removes. Look at what was actually measured.**\n\nA reduction percentage only gains meaning when you also know:\n\n**which substance + which starting concentration + which final concentration + which test method + which capacity.**\n\nThat gives you much more information than a claim such as *'removes up to 99.9% of contaminants'* alone.\n\n## Conclusion\n\nA good test report helps you tell a marketing claim from a measurable result.\n\nDon't just look at the highest reduction percentage. Check which substance was examined, how much was measured before and after filtration, up to which capacity it was tested and who carried out the study.\n\nPay close attention, too, to the difference between **tested according to an NSF/ANSI test method and certified to an NSF/ANSI standard**.\n\nAt Helder. we therefore try to use the original laboratory data as far as possible.\n\nNot because a percentage of 99% or 99.9% sounds impressive in itself, but because only with the data around it can you judge what such a percentage really means.\n\n> **FREQUENTLY ASKED QUESTIONS** \n\n>**What does 99% reduction mean for a water filter?**
\nA reduction of 99% means that the measured concentration of a certain substance was reduced by 99% under the test conditions in question. It does not mean that the substance has disappeared completely from the water.\n\n>**What does <0.01 µg/L mean in a test report?**
\nThis means that the concentration was below the limit stated by the laboratory. Which limit exactly is meant, for example a reporting limit or a detection limit, has to be clear from the laboratory report in question. It does not automatically mean the concentration was zero.\n\n>**What is the difference between NSF/ANSI 42, 53 and 401?**
\nNSF/ANSI 42 covers, among other things, aesthetic effects and specific reduction claims for, for example, chlorine, taste and odour. NSF/ANSI 53 contains requirements for specific health-related reduction claims. NSF/ANSI 401 focuses on specific reduction claims for so-called emerging compounds, including certain medicines, pesticides, herbicides and other chemical substances.\n\n>**Is tested according to NSF/ANSI the same as NSF certified?**
\nNo. A laboratory can examine a filter according to a test method from an NSF/ANSI standard without the product automatically being NSF certified as a result. Certification includes additional assessments and, with ongoing certification, checks as well.\n\n>**Why is the tested capacity important?**
\nA reduction percentage tells you more when you know after how many litres of water the result was measured. A high reduction at the start of a test says less about performance over the service life than several measuring points over a longer test period.\n\n>**Is the tested capacity the same as the service life of the filter?**
\nNot necessarily. The tested capacity indicates up to which point a certain performance has been examined. The recommended replacement interval of a filter may be different, and the actual service life depends on water quality and use, among other things.\n\n>**Can I compare the reduction percentages of two water filters directly?**
\nOnly if you also take into account the substance examined, test method, starting concentration, measuring points and tested capacity. Two percentages from different laboratory tests are therefore not always directly comparable.\n\n## Sources\n\n- [NSF: Water Filtration, Testing and Certification](https://www.nsf.org/water-systems/water-filtration)\n- [NSF: Water Filters FAQ](https://www.nsf.org/about-nsf/faqs/water-filters-faqs)\n- [NSF: Certification vs. Compliance](https://www.nsf.org/knowledge-library/certification-vs-compliance-what-is-the-difference)\n- [NSF: NSF/ANSI 42, 53 and 401 Filtration Systems Standards](https://www.nsf.org/knowledge-library/nsf-ansi-42-53-and-401-filtration-systems-standards)",
"product_ids": [],
"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:46:10Z"
},
{
"title": "Microplastics in tap water: what are they, how do you measure them and what helps?",
"titles": {
"en": "Microplastics in tap water: what are they, how do you measure them and what helps?",
"de": "Mikroplastik im Leitungswasser: Was ist das, wie misst man es und was hilft?",
"nl": "Microplastics uit kraanwater: wat zijn het, hoe meet je ze en wat helpt?"
},
"kicker": "Explained · microplastics in tap water",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/microplastics-uit-kraanwater/",
"de": "https://waterfilterhouse.com/de/ratgeber/microplastics-uit-kraanwater/",
"nl": "https://waterfilterhouse.com/nl/uitleg/microplastics-uit-kraanwater/"
},
"url": "https://waterfilterhouse.com/en/guides/microplastics-uit-kraanwater/",
"intro": "Microplastics are tiny plastic particles that can also be found in drinking water. How many particles are found depends heavily on the measuring method used. Some water filters can reduce microplastics, but look at specific test results. A general filter claim or a stated pore size is not enough proof that microplastics have actually been tested.",
"body_markdown": "## What are microplastics?\n\nMicroplastics are very small particles of plastic. An upper limit of **5 millimetres** is often used.\n\nThey can enter the environment directly as small particles, or form when larger pieces of plastic slowly break apart.\n\nExamples of sources are:\n\n- tyre wear;\n\n- synthetic clothing fibres;\n\n- paint and coatings;\n\n- packaging material;\n\n- breakdown of larger plastic waste.\n\nMicroplastics are now found in water, soil and air.\n\n## And what are nanoplastics?\n\nBesides microplastics, people increasingly talk about **nanoplastics**. These are even smaller plastic particles.\n\nThe precise boundary between microplastics and nanoplastics is not defined in the same way everywhere. Measuring very small plastic particles in particular is technically difficult.\n\nThat distinction matters when you look at water filters.\n\nIf a filter has been tested for microplastics above a certain size, that does not automatically mean it also removes all the smaller nanoplastics.\n\n## Are there microplastics in Dutch tap water?\n\nMicroplastics have been detected in drinking water. That does not mean every glass of Dutch tap water contains a fixed amount of microplastics.\n\nThe numbers measured can differ greatly between studies. An important reason for this is that different sampling and analysis methods are used. Very small plastic particles in particular are hard to measure reliably.\n\nThe RIVM states that Dutch tap water is of good quality. The presence of microplastics therefore does not mean that Dutch tap water should be regarded as unsafe.\n\n## Are microplastics in drinking water harmful?\n\nOn the basis of the data available, not all questions about possible health effects can be answered yet.\n\nIn its assessment of microplastics in drinking water, the World Health Organization (WHO) concluded that, on the basis of the data available at the time, there was no indication of a clear health risk. At the same time, the WHO pointed to important knowledge gaps and the need for more research.\n\nThe RIVM also states that little is yet known about the effects of microplastics on the human body.\n\nIt is therefore important to keep two things apart:\n\n**microplastics are demonstrably present in our living environment, but that does not automatically mean that the amounts in Dutch tap water pose a health risk.**\n\n## How are microplastics in water measured?\n\nYou cannot reliably measure microplastics with an ordinary household water test.\n\nLaboratories use specialised analysis methods for this. Depending on the study, microscopic and spectroscopic techniques may be used, for example.\n\nThe method used influences which particles are found.\n\nA study that can only detect larger particles may therefore give a different result from a study that can measure much smaller particles.\n\nThat makes it difficult to compare the numbers of microplastics from different studies directly.\n\n## Can you filter microplastics out of tap water?\n\nYes, certain water filters can reduce microplastics.\n\nWith particles, physical filtration plays an important role. Actual performance does depend, however, on the complete filter element, the size of the particles and the conditions in which the filter was tested.\n\nThat is why we consider a statement such as:\n\n**'This filter can hold back very tiny particles, so it removes microplastics.'**\n\ninsufficient proof of a specific microplastics claim in itself.\n\nA specific laboratory test or certification for microplastics reduction tells you much more.\n\n## BOROUX Foundation and microplastics\n\nMicroplastics reduction has been specifically examined for the BOROUX Foundation filters.\n\nBOROUX Foundation is certified by WQA for microplastics reduction according to **NSF/ANSI/CAN 401**. The certification relates to microplastics in the tested particle category of **≥0.5 µm to ≤1.0 µm**.\n\nThe Performance Data Sheet states an average reduction of 98.9% for this test.\n\nThat matters because this is not just a theoretical assumption based on filter material or pore size. Microplastics reduction is actually a specific claim within the certification.\n\nHere too there is a limitation:\n\n**a certification for this tested particle size does not automatically mean that all smaller nanoplastics are removed.**\n\n## Black Berkey and microplastics\n\nWith **Black Berkey filters**, the situation is different.\n\nBerkey has published extensive laboratory data for various types of contaminants and very small particles.\n\nFor microplastics, however, according to Berkey itself, no specific test has been carried out on which an official reduction claim can be based.\n\nBerkey states that other filtration data indicate that Black Berkey filters can probably hold back larger microplastic particles. That is not the same as a specific laboratory test for microplastics, however.\n\nThat is why we do not quote a specific reduction percentage for microplastics for Black Berkey.\n\n## Coldstream FTO Plus and microplastics\n\nThe Coldstream FTO Plus filter combines a ceramic outer layer with activated carbon and other filter media.\n\nSpecific data on particles and microplastics have also been published for this filter.\n\nThe Performance Data Sheet of the Coldstream FTO Plus CF163W states a reduction of **99.9% for Particle Reduction Class 1, including microplastics**.\n\nThat is an important difference from a general assumption based on the pore size of a ceramic filter. In this case, the manufacturer actually mentions microplastics in the published performance data.\n\nSome caution is needed when comparing with BOROUX. Different test methods, particle sizes and test conditions can mean that the percentages are not directly comparable.\n\n## What does NSF/ANSI 401 say about microplastics?\n\nNSF/ANSI 401 is used for various so-called *emerging compounds* and also contains a specific claim for microplastics reduction.\n\nAn important detail is that a filter certified to NSF/ANSI 401 is not automatically certified for every possible claim within that standard.\n\nSo you need to check whether microplastic reduction is actually part of the certification of the filter in question.\n\nThat principle also applies to other NSF/ANSI standards.\n\nYou can read more about this in our article [What does a water filter test report contain?](/uitleg/watstaaterein-testrapport/).\n\n## Which water filter should you choose for microplastics?\n\nIf microplastics are an important reason for you to filter tap water, look above all at these points:\n\n**1. Has the filter been tested specifically for microplastics?**\n\n**2. Which particle size was examined?**\n\n**3. Is it a laboratory test or a certification?**\n\n**4. Under which conditions was the performance examined?**\n\n**5. Does it talk only about microplastics, or about nanoplastics too?**\n\nThat last distinction in particular is important.\n\nA filter can perform excellently for the microplastics it was tested on, without that proving that all much smaller plastic particles are removed as well.\n\n## Conclusion\n\nMicroplastics occur in our living environment and have also been detected in drinking water. How many particles are found depends heavily on the measuring method used, and smaller particles in particular are difficult to study.\n\nDutch tap water is of good quality. An additional water filter is therefore not necessary to drink Dutch tap water safely.\n\nIf you still want to reduce microplastics further, you can look for a water filter with demonstrable performance for microplastics. Specific laboratory tests and certifications tell you more here than a theoretical pore size alone.\n\nFor BOROUX Foundation, microplastics reduction is specifically certified according to NSF/ANSI/CAN 401, with an average reduction of 98.9% for the tested particle category. For Coldstream FTO Plus, the Performance Data Sheet states a 99.9% reduction of Particle Reduction Class 1, including microplastics. According to Berkey itself, Black Berkey has no specific microplastic test on which an official reduction claim can be based.\n\nYou cannot automatically compare the percentages of different filters directly when the test methods and conditions differ.\n\n**So don't just look at how finely a filter says it filters, but above all at what has actually been tested.**\n\n> **FREQUENTLY ASKED QUESTIONS** \n\n>**Are there microplastics in Dutch tap water?**
\nMicroplastics have been detected in drinking water. The numbers measured differ per study and analysis method. Their presence does not mean that Dutch tap water is regarded as unsafe.\n\n>**Can I measure microplastics myself?**
\nNot reliably with an ordinary household water test. Specialised laboratory techniques are needed to identify and measure microplastics.\n\n>**Can a water filter remove microplastics?**
\nCertain water filters can reduce microplastics. Preferably look at specific laboratory tests or certifications, and check which particle size was actually examined.\n\n>**Does BOROUX Foundation filter microplastics?**
\nYes. BOROUX Foundation is certified by WQA according to NSF/ANSI/CAN 401 for microplastics reduction in the tested particle category of ≥0.5 µm to ≤1.0 µm. The Performance Data Sheet states an average reduction of 98.9%.\n\n>**Does Coldstream FTO Plus filter microplastics?**
\nIn the Performance Data Sheet of the FTO Plus CF163W, Coldstream states a reduction of 99.9% for Particle Reduction Class 1, including microplastics.\n\n>**Does Berkey filter microplastics?**
\nBerkey states that Black Berkey Elements have not been tested specifically for microplastics. Other filtration data make a reduction of larger plastic particles plausible, but that is not the same as a specific microplastic test.\n\n>**Are microplastics the same as nanoplastics?**
\nNo. Nanoplastics are even smaller plastic particles. Definitions and measuring methods differ, and research into these very small particles is complex. A test for microplastics therefore does not automatically prove the same reduction for smaller nanoplastics.\n\n## Sources\n\n- [RIVM: Drinking water quality](https://www.rivm.nl/drinkwater/drinkwaterkwaliteit)\n- [RIVM: Plastics and health](https://www.rivm.nl/plastics/gevolgen-gezondheid)\n- [WHO: Microplastics in drinking-water](https://www.who.int/publications/i/item/9789241516198)\n- [NSF: certified filters with Microplastics Reduction](https://info.nsf.org/Certified/DWTU/Listings.asp?ProductFunction=401%7CMicroplastics+Reduction)\n- [BOROUX Foundation: independent tests and certifications](https://boroux.com/pages/what-does-boroux-foundation-filter-remove)\n- [BOROUX Foundation: Performance Data Sheet](https://boroux.com/pages/performance-data-sheet)\n- [Berkey: Black Berkey Elements and plastic fibers](https://support.berkeywater.com/black-berkey-elements-plastic-fibers/)\n- [Coldstream FTO Plus CF163W: Performance Data Sheet](https://www.alternatievemiddelen.nl/wp-content/uploads/2026/10/Coldstream-FTO-PLUS-filterelementen_testrapport.pdf)",
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"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:46:10Z"
},
{
"title": "Limescale at home and limescale in your filter: what is the difference and how do you keep your system clean?",
"titles": {
"en": "Limescale at home and limescale in your filter: what is the difference and how do you keep your system clean?",
"de": "Kalk im Haus und Kalk im Filter: Was ist der Unterschied und wie halten Sie Ihr System sauber?",
"nl": "Kalk in huis en kalk in je filter: wat is het verschil en hoe houd je je systeem schoon?"
},
"kicker": "Guide · limescale at home and in your filter",
"urls": {
"en": "https://waterfilterhouse.com/en/guides/kalk-in-huis-en-kalk-in-je-filter/",
"de": "https://waterfilterhouse.com/de/ratgeber/kalk-in-huis-en-kalk-in-je-filter/",
"nl": "https://waterfilterhouse.com/nl/uitleg/kalk-in-huis-en-kalk-in-je-filter/"
},
"url": "https://waterfilterhouse.com/en/guides/kalk-in-huis-en-kalk-in-je-filter/",
"intro": "Limescale in your tap water is a natural phenomenon, but it behaves differently in your household than in your water filter. Find out why limescale builds up in your gravity filter, how to tell it apart from blockages and what you can do about it without damaging your filter.",
"body_markdown": "## What exactly is limescale?\nLimescale consists of calcium and magnesium salts that occur naturally in groundwater. In the Netherlands, hardness varies considerably by region. According to RIVM data, the water in the east and south of the country is often hard, while the water in the west and north is softer. Over time, hard water leaves white deposits on taps, shower heads and in your washing machine. That is the same limescale you can also come across in your water filter.\n\n## Limescale in your gravity filter\nA gravity filter such as the Berkey, BOROUX or Pure Filters is not designed to remove limescale from the water. The filter elements capture particles, bacteria, chlorine and other contaminants. When you filter hard water, the calcium and magnesium cannot dissolve completely during the filtering process. It precipitates as a white, grainy deposit on the outside of the filter element or in the lower chamber. This is not a defect and does not mean your filter is broken. It is simply a sign that the filter is processing hard water and that the pores are temporarily covered by the precipitate.\n\n## Maintenance versus replacement\nIt is important to distinguish limescale deposits in your filter from normal wear. A filter element lasts a long time, but its performance can temporarily drop because of limescale or a build-up of particles. If the water drips more slowly or the taste changes, cleaning is often the first step. For Black Berkey and BOROUX Foundation™ Black elements, we recommend cleaning regularly with a scouring agent developed specifically for this purpose. The BOROUX filter and system maintenance kit (48921) contains everything you need to clean your elements safely without damaging the microstructure.\n\nIf you are switching from a ProOne system to a gravity filter, note that the famous ProOne element is really called Coldstream FTO PLUS. This element comes from an English factory and is supplied by Alternatievemiddelen.nl. Existing British Berkefeld systems also carry on running on Coldstream FTO PLUS, because British Berkefeld stopped selling through dealers. These elements work on the same gravity principles and call for similar maintenance.\n\n## How do you prevent too much limescale build-up?\nYou cannot influence the hardness of your tap water, but you can be mindful of how you filter hard water. Do not filter too much water in a row without a break. After use, let the filter drain and leave it to dry on a clean surface. Clean the elements according to the manufacturer's instructions. With very hard water you may need to carry out maintenance more often, but that does not mean you will need a new element sooner. A well-maintained gravity filter lasts for years.\n\n> **In short.** Limescale in your gravity filter is a normal precipitation product of hard water, not a defect. The filter does not remove limescale, but captures particles. Regular cleaning with a suitable maintenance product keeps the flow rate up. Only replace elements if the flow does not recover after cleaning or if their service life has expired.\n\n## Frequently asked questions\n**Does a water filter remove limescale from the water?**\nNo. Gravity filters and ceramic elements are not designed for softening. They capture particles and contaminants. Limescale remains present in the filtered water, but it often becomes less visible because coarser particles are held back. For softening you need a separate water softener.\n\n**How often should I clean my filter element?**\nThis depends on the water hardness in your region and on your water consumption. With average use, once every two to three months is enough. With hard water or intensive use, weekly cleaning may be necessary. Always use a clean brush and a mild scouring agent intended specifically for filter elements.\n\n**Can I clean my filter with vinegar or citric acid?**\nAcid can damage the microstructure of ceramic and carbon elements. We advise against using household acids. Choose a maintenance kit that has been tested for compatibility with the filter materials instead. That way you preserve the filter capacity and the service life of your element.",
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"brand": null,
"created": "2026-10-16T08:42:17Z",
"updated": "2026-10-16T10:43:45Z"
}
]
}