Frequently asked questions

BOROUX Foundation™ Black filters work by absorbing and retaining contaminant molecules. The carbon attracts molecules with a particular chemical charge and absorbs them. They bind to the carbon, much as a magnet attracts metal. The tiny pores of the carbon block are so small that they physically block and trap small particles. It is comparable to a sieve or a colander.

Yes. The BOROUX Foundation™ Black filter is designed to fit most gravity water filter systems with filters in the upper chamber. This includes gravity water filters from brands such as Berkey, British Berkefeld, ProOne, Phoenix, Aqua Logic, Monderma, Pure Filters and Newton, among others.

The BOROUX Legacy™ water filter is a gravity water filter. It has one upper and one lower chamber. The BOROUX Foundation™ Black filters are installed in the upper chamber. Water is poured into the upper chamber, after which gravity pulls the water through the BOROUX Foundation™ Black filters into the lower chamber. The drinking water can then be dispensed through a tap at the bottom of the lower chamber.

If the filter won’t prime properly, try the following:

• let the filter soak in water overnight, see the instruction video
• clean the filter and then prime it again, see the instruction video
• use a primer for this, see product

A failed red dye test can indicate incorrect installation. Check the placement of the wing nuts (outside of the upper chamber) and washers (inside of the upper chamber) once more.

Prime the filter(s) again and repeat the test. If it keeps failing, please contact us.

It is normal for about 2.5 to 5 cm of water to remain in the upper chamber. Because the BOROUX Legacy™ water filter is a gravity water filter, it relies on the pressure and weight of the water to push it down and through the filters. As the water flows into the lower chamber, there is less and less weight pushing it down (the water pressure in the upper chamber decreases). In addition, the water cannot flow through the plastic Stem Saver.

You can discard the remaining water if you like, when you fill the upper chamber of your BOROUX Legacy™ water filter again.

White residue is mineral deposits. It is harmless and, as far as the black filters are concerned, no reason to replace them. If it is visible on the black filter, rinse it off under running water and wipe it away. If it is visible on the chambers or the tap, scrub it away with a mixture of half water and half vinegar. You can also let the tap soak in this mixture.

If your water filter leaks at the tap, check whether the installation is correct.

If your water filter leaks where the two chambers meet, your water filter is too full. Only fill the upper chamber when the lower chamber is (almost) empty.

The upper chamber of your BOROUX water filter should have run through completely in about 2 hours on average (a small layer remains). The better the priming has succeeded, the faster the flow rate will be. So if it takes considerably longer than 2 hours, we advise priming again. For a first use, the priming probably did not succeed properly and there is still too much air in the BOROUX Foundation™ Black filter elements. With filters that have been in use for longer, this is a sign to prime again.

Priming makes the air leave the filters again, so they flow faster again. For this you can use the Priming Button, the Black Berkey Primer or the blue Primer Rite. See also the instruction videos.

Is this the first time you are using the BOROUX Legacy™ water filter? Then the following is important: – the filter speed will increase somewhat further during the first 12 to 24 hours.

If the speed stays low and quite a lot of water remains in the upper chamber after well over 2 hours, please contact us and we will gladly help you further.

That can happen! No two BOROUX Foundation™ Black filter elements are the same, they are all unique. As a result, one filter element may run through faster than another. The differences arise during production (the baking process), and you often see that filters from the same box are roughly the same, but this need not be the case. It is therefore not a problem and nothing to worry about.

If you notice a marked difference in the filter speed of the BOROUX Foundation™ Black filters, this is a signal to prime again. Before you start cleaning, first try to solve it by priming the BOROUX Foundation™ Black filter elements once more. Cleaning should not be done too often, and when using tap water once every 6 months is enough. If priming does not improve the filter speed, it is time to clean. But after cleaning you need to prime again as well.

Priming makes the air leave the filters again, so they flow faster again. After some time in use, air slowly gains the upper hand in the filters again. For this you can use the Priming Button, the Black Berkey Primer or the blue Primer Rite. See also the instruction videos.

If you do have to clean the filters, see the instructions under the heading “Cleaning, maintaining and storing”.

It is good to know that a BOROUX water filter does not remove limescale from the water entirely. Larger amounts are reduced and synthetic scale is removed. However, a BOROUX water filter retains good minerals (which naturally belong in water and are good for people) in the water. And limescale (calcium) is one of them. So you keep the mineral calcium in the water, and this can still cause some scale. In short, a BOROUX water filter is not there to remove limescale from the water.

If water leaks from the tap connection, it is most likely because the tap is not properly fitted. So empty the lower chamber and remove the tap. Then check whether all parts are in the right place. It is important that you have 1 rubber washer on the outside and 1 rubber washer on the inside. Then put the tap back and tighten the nut (on the inside) as far as it will go. Then hold the nut on the inside and turn the tap on the outside. You will notice that it becomes even tighter. Keep doing this until it won’t turn any further. If the tap is not straight, do the following: release the nut on the inside and turn only the tap on the outside until it is straight. It then turns as a whole. If you have accidentally turned too far, do NOT turn it back. That would loosen it again. If you have gone too far, keep turning it all the way round until it sits properly again. If all is well, the tap should no longer leak at the connection.

If water comes out between the upper and lower chamber of your BOROUX water filter, it means the lower chamber is too full. This happens when the upper chamber is filled again while the lower chamber is not yet empty. Filtering simply continues, and the lower chamber then overflows. The water then comes out between the two chambers. The best approach is to fill the upper chamber completely the first time. Let this water run through. When you notice that the lower chamber is almost empty (via the sight glass tap or via the pressure of the water), fill the upper chamber completely again. You can do this because the upper chamber is slightly smaller than the lower chamber, and in addition the upper chamber contains the filters, which take up space. The lower chamber therefore has excess capacity relative to the upper chamber. By doing it this way, you prevent water leaking between the two chambers.

The BOROUX Foundation™ Black filter elements are designed to remove heavy metals, but will not remove mineral salts added by a water softener. A water softener adds mineral salts to the water to make it softer. The salt used to soften water is not extracted by a BOROUX Foundation™ Black filter element and even causes the element to clog. You can still use a BOROUX water filter if it is possible to bypass the water softener. Most water softeners have a bypass valve or a way to get water before it passes through the softener. We therefore strongly recommend using that water instead of running softened water through your BOROUX Foundation™ Black filter elements.

• The chambers and taps are made of AISI 304 stainless steel, of food-safe quality and highly corrosion-resistant.
• BOROUX Foundation™ Black filters are blocks of activated carbon.
• The Stem Saver (holder of the BOROUX Foundation™ Black filters) and the blocking plugs are made of BPA-free, food-safe plastic.
• The sealing rings are made of silicone.

A special blend of activated carbon.

Proudly made in the USA! The plastic Stem Saver™ comes from China.

The BOROUX Legacy™ water filter is designed in Colorado and made in China in a reputable, technologically advanced factory.

Yes, stainless steel can rust, although the chance is smaller than with other types of steel. Stainless steel contains chromium, which forms a protective oxide layer on the surface that helps prevent corrosion. However, if this protective layer is damaged or if the stainless steel is exposed to harsh environmental conditions, such as high humidity or substances containing chloride, it can still rust. Regular maintenance and proper care can help prevent rust formation in stainless steel.

Clean the stainless steel chambers and the tap monthly with washing-up liquid and warm water.

Clean the BOROUX Foundation™ Black filters every 3-6 months with cold water and a scouring pad.

For more information, see the manual or the instruction videos in our library.

If you have used your elements:

How to store them depends on how long the BOROUX Foundation™ Black filter elements will not be used:

If the filters will not be used for 4 to 15 days and you want to avoid priming again, remove the filters from the water filter, place them in a sealable bag or container and put the filters at the front of the refrigerator to prevent freezing. This keeps the filters largely saturated (wet), so priming again is usually not necessary. If the filters work more slowly than normal for any reason, prime them again until the outer wall of the filter begins to sweat water droplets for 10 seconds.

For long-term storage we recommend drying the filters and storing them closed. It is important that they are bone dry before being stored long term, to prevent possible bacterial growth. One way to dry your filters is to leave them on a windowsill for one to three days and let them air dry. We also offer a tool that helps with both priming and drying (purging). This is the BOROUX Automatic Filter Primer Pump (electric) or Black Berkey Primer. The advantage of drying (purging) the BOROUX Foundation™ Black filter elements is that they dry very quickly. Once the filters are bone dry, place them in a storage bag such as a large, sealable bag. The elements are extremely powerful and can absorb odours and smoke from the air. By sealing them in a bag, they cannot absorb odours from the air. When you are ready to use the filters again, clean them by scrubbing the outside with a scouring sponge or a hard brush. Then prime the filters again, manually or with the BOROUX Automatic Filter Primer Pump (electric) or Black Berkey Primer, before putting them back into the water filter.

In theory, the shelf life of the BOROUX Foundation™ Black filter elements is unlimited.

**Please note that the storage methods above only apply to the BOROUX Foundation™ Black filter elements.

If you have never used the elements:

If the elements are unopened and still in their original packaging, make sure you do not store them in a room with strong smells (such as a laundry room or garage). The elements have carbon as one of their components, so they may absorb the smells of the room in which they are stored. If they are kept in a laundry room, for example, they may pick up the smell of strongly scented items such as washing powder.

** If you also store the upper and lower chambers of your water filter, it is best to empty both chambers before storing them. Water that stands still for a long time promotes the growth and production of bacteria and mould. We recommend washing your water filter with soapy water before letting it dry.

BOROUX Foundation™ Black filters have been tested by IAPMO R&T Lab NJ, an ISO/IEC 17025 accredited laboratory. See below the complete BOROUX test report:

Complete BOROUX test report

See below all the individual reports:

• Test report BOROUX: Chloramine
• Test report BOROUX: Lead 6.5 pH
• Test report BOROUX: Lead 8.5 pH
• Test report BOROUX: Chlorine
• Test report BOROUX: Uranium Mercury Gross Beta Cesium 6.5 pH
• Test report BOROUX: Mercury 8.5 pH
• Test report BOROUX: PFAS
• Test report BOROUX: Chloroform
• Test report BOROUX: Pharma G1
• Test report BOROUX: Pharma G2
• Test report BOROUX: Pharma G3
• Test report BOROUX: Glyphosate
• Test report BOROUX: Chromium III Cadmium Selenium 6.5 pH
• Test report BOROUX: Chromium III Cadmium Selenium 8.5 pH
• Test report BOROUX: Chromium VI 6.5 pH
• Test report BOROUX: Chromium VI 8.5 pH

Test reports are added from time to time. We update this page regularly, but for all current laboratory test results of the BOROUX water filter: click here. You will be redirected to the manufacturer's website, where all results are gathered on one page. These are all the tests carried out with the BOROUX Foundation™ Black filter elements, which are the filter elements of the BOROUX water filter.

View the full list with the latest test results.

Fluoride is not filtered by the BOROUX Foundation™ Black filters. The first tests with the BOROUX Foundation™ Black filters showed that fluoride was not filtered effectively. Although fluoride was reduced, this was not the case over a large number of litres. True to BOROUX's core values of transparency, they did not extrapolate any data and make no false claims. Fluoride is therefore not filtered by the BOROUX Foundation™ Black filters to their strict standards.

However… with the additional BOROUX Proactive™ Fluoride filters they remove more than 99% of the fluoride in the first 1,000 litres. The patented upflow design and the double-layer nano-carbon filtration of these BOROUX Proactive™ Fluoride filters maximise filtration. The fluoride filters, mounted in durable stainless steel housings, are compatible with BOROUX Foundation™ Black filters and Black Berkey filters and deliver more than 3,500 litres of clean, fluoride-reduced water per pair.

The BOROUX Foundation™ Black filters are certified to NSF/ANSI/CAN 372 lead-free. The BOROUX Foundation™ Black filter elements are currently being tested for additional certifications. All certification tests are carried out by the Water Quality Association (WQA).

A TDS meter does not measure much change between unfiltered water and water filtered with a BOROUX. This is normal, and the explanation lies in what a TDS meter actually measures. According to tdsmeter.com, “Total Dissolved Solids (TDS) is the total amount of mobile charged ions, including minerals, salts or metals, dissolved in a given volume of water, expressed in units of mg per unit volume of water (mg/L), also referred to as parts per million (ppm). TDS is directly related to the purity of water and the quality of water purification systems and affects everything that consumes, lives in or uses water, whether organic or inorganic, for better or for worse.”

This statement is both correct and incorrect. It is correct about what a TDS measurement consists of, namely the “total amount of mobile charged ions, including minerals, salts or metals, dissolved in a given volume of water”. It is incorrect in its conclusion that TDS is related to the purity of the water and the quality of the water purification system. If the measure of a water purification system were how close it could bring the water to pure H2O, it might perhaps be right. But people need minerals to live. So beneficial minerals in your water are actually a good thing. A high-quality water purification system should filter out things that are harmful to your body, but leave the beneficial things such as minerals behind. BOROUX Foundation™ Black filter elements are designed to leave healthy and beneficial minerals in the water and to extract the unwanted heavy metals such as lead and mercury, as well as sedimentary minerals such as iron oxide and aluminium.

So if you use a TDS meter, you will find that the reading is about the same both before and after the water has passed through the BOROUX Foundation™ Black filter elements. And that is correct. The BOROUX Foundation™ Black filter elements retain all beneficial minerals. So, of the things a TDS meter will actually detect, the BOROUX Foundation™ Black filter elements will only remove the unwanted heavy metals such as lead and mercury, as well as sedimentary minerals such as iron oxide and aluminium. That is why the TDS value will not change much, unless you have a considerable amount of heavy metals or sedimentary minerals in your water.

A TDS meter does not measure the amount of biological and chemical contaminants (including, for example, chemicals, medicines, hormones, many pesticides and their residues, bacteria and viruses). Most importantly, do not rely on a TDS meter alone to measure whether your water is good. You can have water with a low TDS level that contains harmful bacteria. You can have water with a high TDS value that is perfectly safe (e.g. pure, uncontaminated sea salt water … although you would not drink it, but that is only because the mineral is salt). So make sure you know what a TDS meter actually measures.

IMPORTANT INFORMATION FIRST The red dye test is only there to check that your water filter has been assembled correctly, so that no water comes out other than through the stems of the BOROUX Foundation™ Black filter elements, and that the filters are not exhausted. There are no independent test results showing by what percentage the red food dye is filtered out. It is therefore not officially claimed that this contaminant is reduced. If the instructions below are not followed and, for example, a higher concentration of red dye or a different red dye is added, it is likely that it will not be reduced by 100%. It is therefore important to follow the instructions below carefully, in particular the amount of red dye and not carrying out the test more than twice a year.

The BOROUX Foundation™ Black filter elements are powerful enough to remove red food dye from water. By carrying out a red dye test you can be sure that your water filter system is working properly.

GUIDELINES

• We recommend carrying out this test on first use and every six months thereafter (after cleaning) to make sure the BOROUX Foundation™ Black filter elements are working properly.
• The red dye test is intended only for the BOROUX Foundation™ Black filter elements and NOT for other filter elements (such as fluoride filters), which do not filter out the dye.
• Make sure the dye is RED. Red food dye (unlike the other colours) contains no minerals, so the element recognises it as a contaminant. Also do not use natural red dye (such as beetroot juice), as this is not recognised as a contaminant either. The idea is to use a synthetic red dye, so use the original red dye.
• The red dye test must be carried out after the BOROUX Foundation™ Black filter elements have been primed.

CARRYING OUT THE TEST

NOTE: watch our instruction videos for a video of how to carry out the red dye test.

1. Start with an empty water filter system (upper and lower chamber) and remove any fluoride filters (if installed).
2. Place only the upper chamber (with the BOROUX Foundation™ Black filter elements installed) on glasses of a similar size (so the stems of the filters protrude into the glass). This makes it easy to see directly which filter passes and which fails the test.
3. In a separate jug, add 3 drops (= 0.15 ml) of dye per litre of water and mix (with one bottle of original red dye you can carry out a full test several times). Pour the red water into the upper chamber until the filters are completely submerged. Please note: Never pour red dye directly from the bottle onto the filters or into the upper chamber. Always mix the dye with water beforehand in a separate jug.
4. Let the water filter from the upper chamber into the glasses below. When the glasses are three-quarters full, pour out the remaining water from the upper reservoir. Please note: The glasses may fill at different speeds.
5. Check the water in each glass. It should be clear, without a pink or red tint. If the water in one of the glasses is red or has a pink tint, that specific filter may be defective or exhausted. See below.

IF A RED COLOUR IS OBSERVED IN THE WATER, CHECK THE FOLLOWING:

1. Are the wing nuts tight enough? Do not tighten the wing nuts with tools; they must be tightened by hand until you feel resistance, then that is sufficient. If the wing nuts are too tight, this can damage the thread of the stem and/or the grooves of the wing nut. This can affect the seal. If this has happened, please contact us.
2. Are you using natural red food dye or a dye of another colour? Only synthetic red food dye is recommended for this test.
3. Is the black ring of the BOROUX Foundation™ Black filter elements inside the upper chamber, and is the wing nut on the underside tightened? If the black ring is on the outside of the lower chamber (that is, directly against the wing nut), this is not a good seal. The test will therefore fail. Place the black ring on the inside of the upper chamber and carry out the test again.
4. Do the blocking plugs close the unused holes properly (if applicable)? Are the blocking plugs firmly installed so that the hole is really sealed? For blocking plugs with a bolt and nut, a sealing washer must be fitted on both sides (not on one side only). If the plugs leak, the test will fail. Install the blocking plugs more firmly and carry out the test again.
5. Are you retesting a filter element that has failed? Then make sure you first rinse this filter element and prime it again before testing again. Also make sure that all water has been removed from the lower chamber (or glass). If you use the lower chamber or a glass to collect water, first rinse it out thoroughly with clean water. Now you are ready to repeat the test.
6. If you have done all of the above and a filter element still fails the red dye test, please contact us. The BOROUX Foundation™ Black filter elements come with a one-year warranty.

NOTE: watch our instruction videos for a video of how to carry out the red dye test.

The BOROUX Foundation Black filters are designed for long-term use. However, the actual lifespan 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.

BOROUX gives 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.

Based on our experience with Dutch tap water, we advise replacing the filters after a maximum of three years with average use and when using tap water. 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 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 provide a definitive answer.

Please note: the test results and maximum capacities differ per contaminant. Always consult the most up-to-date information and the BOROUX test results.

You may notice a subtle earthy or mineral-like taste when you use your new BOROUX Proactive™ Fluoride filters for the first time. This is completely normal and temporary.

These filters use high-quality filter media that can initially give off a harmless taste. To prevent or resolve this, we recommend priming each filter for at least 10 minutes with higher water pressure before you install it. Using warm water (approximately 38 °C) is an important tip here. In tests, this method resolved the taste issue in 100% of cases.

For the most effective priming, use the blue silicone primer supplied with the filters or the BOROUX Automatic Filter Primer Pump (electric). These help to rinse the filters completely and properly, and make sure your water tastes great from the start.

Yes, the BOROUX Proactive™ Fluoride filters are designed to be fully compatible with the Berkey water filter. They attach directly to the Black Berkey filters and therefore also hang in the lower chamber, just like Berkey's fluoride filters. This means you can keep using your existing Berkey setup while also benefiting from BOROUX's advanced fluoride-reducing technology. They also fit, of course, in conversions of other brands of gravity water filters, as long as Black Berkey filters or BOROUX Foundation™ Black filters are used.

Do you need help determining compatibility? Please contact us!

The first filtration stage takes place when the water flows through the proven BOROUX Foundation™ Black filters with activated carbon. The BOROUX Proactive™ Fluoride filter is screwed onto and attached to the stem of the BOROUX Foundation™ Black filter. The second filtration stage takes place when the water flows through the dual-action BOROUX Proactive™ Fluoride filter.

After the water has passed through the filters in the upper chamber, it first comes into contact with the inner layer of the highly efficient granulated carbon filters in the lower chamber. The water then filters through the patented nano-carbon outer layer. Thanks to the patented upflow design of the stainless steel housing, the water stays in contact with the outer layer for a long time, which ensures superior filtration. The filtered water leaves the housing through the outlet holes at the top. This results in a nearly even use of the entire surface of the fluoride filters, from bottom to top.

Arsenic has not been tested yet.

The lifespan of the filter varies depending on the water source (the quality of the water going in) and usage. It is recommended to replace filters at 3,750 litres, which is approximately 6-12 months.

The BOROUX Proactive™ Fluoride filter consists of two different layers. The inner layer is granulated carbon: small, loose grains of a mixture of different carbons are packed into the centre of the cylinder filter. The outer layer of the filter is a nano-carbon. This mix of specialised carbon is moulded into shape.

Proudly made in the USA! So not in China or any other Asian country.

Yes, you need one BOROUX Proactive™ Fluoride filter for each BOROUX Foundation™ Black filter in your system. The BOROUX Proactive™ Fluoride filters are designed as a 1-to-1 product, meaning each fluoride filter is connected directly to one BOROUX Foundation™ Black filter.

This guarantees balanced flow, good filtration performance and maximum fluoride reduction throughout your entire system.

Yes, the stainless steel holder is essential for good performance. It supports the upflow design, which guides water from bottom to top, reducing the flow rate and increasing the contact time between water and filter media. This optimised interaction improves fluoride reduction and overall effectiveness.

With a fully charged battery you can prime at least 10 filters before you need to recharge the pump. It takes approximately 90 seconds to fully prime one filter.

The light on your primer pump gives you a quick insight into the current battery status. This is what each colour and light pattern means:

Solid green: fully charged and ready for use Flashing green: charging Flashing red: battery level is below 25%, charge soon Solid red / no light / empty: battery is almost empty, must be charged immediately

If you are not sure whether the pump is working properly, we recommend charging it fully and checking the light again.

No, the Primer Pump is not waterproof. Do not submerge the Primer Pump completely in water.

Yes. The Primer Pump is compatible with Black Berkey filters and BOROUX Foundation™ Black and BOROUX Proactive Fluoride filters (adapter supplied with fluoride filters).

On the contrary, using the Primer Pump guarantees complete and consistent priming, which extends the lifespan of your filter and optimises filtration performance.

Incorrect priming can lead to cloudy water, a lower flow rate, uneven filtration and a shorter filter lifespan. The primer pump ensures consistent, correct priming for optimal filter performance.

The Black Berkey filter elements are designed to remove heavy metals, but will not remove mineral salts added by a water softener. A water softener adds mineral salts to the water to make it softer. The salt used to soften water is not extracted by a Black Berkey filter element and even causes the element to become clogged. You can still use a Berkey water filter if it is possible to bypass the water softener. Most water softeners have a bypass valve or a way to get water before it passes through the softener. We therefore strongly recommend using that water instead of running softened water through your Black Berkey filter elements.

If water comes out between the upper and lower chambers of your Berkey water filter, it means that the lower chamber is too full. This happens when the upper chamber is refilled while the lower chamber is not yet empty. Water simply keeps being filtered, and the lower chamber then overflows. The water then comes out between the two chambers. The best approach is to fill the upper chamber completely the first time and let this water run through. When you notice that the lower chamber is almost empty (via the sight glass tap or via the water pressure), fill the upper chamber completely again. You can do this because the upper chamber is slightly smaller than the lower chamber, and the filters in the upper chamber also take up space. The lower chamber therefore has excess capacity compared to the upper chamber. By doing it this way, you prevent water leaking between the two chambers.

If water is leaking from the tap connection, this is most likely because the tap has not been fitted properly. Therefore, empty the lower chamber and remove the tap. Then check whether all parts are in the right place. It is important that you have 1 rubber ring on the outside and 1 rubber ring on the inside. Then put the tap back and tighten the nut (on the inside) as far as it will go. Then hold the nut on the inside and turn the tap on the outside. You will notice that it becomes even tighter. Keep doing this until it will not go any further. If the tap is then not straight, do the following: release the nut on the inside and turn only the tap on the outside until it is straight. It turns as a whole. If you have accidentally turned too far, do NOT turn it back. That would loosen it again. If you have gone too far, keep turning all the way round until it sits properly again. If all is well, the tap should no longer leak at the connection.

It is good to know that a Berkey water filter does not remove limescale from the water completely. Larger amounts are reduced and synthetic scale is removed. However, a Berkey water filter retains good minerals (which naturally belong in water and are good for people) in the water. And lime (calcium) is one of these. So you keep the mineral lime in the water, and this can therefore still cause some scale. In short, a Berkey water filter is not there to remove limescale from the water.

This is what is known as an airlock. The chambers fit together so perfectly that no air can get in. It is hard to predict beforehand when this will happen, because sometimes they simply fit too perfectly.

There are two ways to solve this problem:

Option 1. Use the Anti-Airlock Clip. If you ordered a Berkey water filter from summer 2022 onwards, you have already received it. This clip is included in the Priming Starter Kit, which has been supplied free with a Berkey water filter since summer 2022. If you do not have the Priming Starter Kit, you can order the Anti-Airlock Clip separately from us, click here. You place the clip on the rim of the lower chamber, with the round side facing outwards. You then put the upper chamber back on. Now enough air can get in, no vacuum forms any more and the water will simply come out properly.

Option 2. You can also try turning the upper chamber into different positions to see whether it fits differently and lets air through. Another solution is to ‘roll’ the lower chamber: – Carefully remove any Black Berkey filter elements from the system and set the upper chamber aside. – If already installed, remove the tap from the lower chamber. – Lay a towel on a smooth, hard surface. Lay the lower chamber on its side on the towel, with the towel held firmly in place. – Apply light pressure to the side of the lower chamber with both hands; roll the chamber back and forth over the hard surface. Focus your attention on the upper part of the lower chamber. This will slightly reshape the lower chamber and allow good airflow between the upper and lower chambers.

If you choose to roll it, it may not be solved after one try, but then you could simply try it once more.

If you notice a clear difference in the filtering speed of the Black Berkey filters, this is a signal to prime them again. Before you start cleaning, first try to solve this by priming the Black Berkey filter elements once more. You should not clean them too often, and when using tap water once every 6 months is sufficient. If priming does not improve the filtering speed, it is time to clean them. But after cleaning you will need to prime them again as well.

Priming makes sure the air leaves the filters, so that water runs through them faster again. After a while in use, air slowly takes over inside the filters again. For this you can use the Priming Button, the Black Berkey Primer or the blue Primer Rite. See also the instruction videos.

If you do have to clean the filters, please see the instructions under the heading “Cleaning, maintaining and storing”.

This can happen! No Black Berkey filter element is the same, they are all unique. As a result, one filter element may run through faster than another. The differences arise during production (the baking process), and you often see that filters from the same box are roughly the same, but this does not have to be the case. It is therefore not a problem and nothing to worry about.

It is perfectly normal for a few centimetres of water to remain in the upper chamber. The Black Berkey filter elements sit on a rim, and of course no water can pass through this rim. In addition, the water pressure is very low when only a little water is left in the upper chamber, so the water can no longer get through. This applies when the water is only just above the rim of the filter element.

You can discard the remaining water if you like, when you refill the upper chamber of your Berkey water filter.

The upper chamber of your Berkey water filter should have run through completely in about 2 hours (a thin layer will remain). The better the priming has worked, the faster the flow rate will be. So if it takes longer than 2 hours, we advise priming again. The first time, this probably means the priming did not work well and there is still too much air in the Black Berkey filter elements. If the filters have been in use for longer, this is a sign to prime again.

Priming makes sure the air leaves the filters, so that water runs through them faster again. For this you can use the Priming Button, the Black Berkey Primer or the blue Primer Rite. See also the instruction videos.

Is this the first time you are using the Berkey water filter? Then the following is important: – the filtering speed will still increase somewhat during the first 12 to 24 hours.

If the speed stays low and water therefore remains in the upper chamber after well over 2 hours, please contact us and we will be happy to help you further.

Yes, the base of a Black Berkey filter element is BPA-free.

There are three different types of blocking plugs:

1. Black blocking plugs come as standard with all Berkey Light water filters and some stainless steel models. The black plugs are made of FDA-approved Buna rubber.
2. Off-white blocking plugs (rubber cork) can be supplied with the Berkey Light models and some stainless steel models. The off-white plugs are made of food-grade M18 pure gum rubber.
3. White blocking plugs (bolt and nut) are used in some stainless steel models. These come with a nut, a screw and two transparent rings. The nut and screw are made of polypropylene. The rings are made of food-grade silicone.

Please note that the water in the lower chamber of your water filter will not touch any of the blocking plugs. The water is filtered before it reaches the lower chamber.

If you have already used the elements:

The Berkey Fluoride & Arsenic filter elements (PF-2) can be stored in the fridge for a short time (see below), but definitely do not store them in the freezer. To do so, take the filters out of the water filter, put them in a sealable bag or container and place the filters at the front of the fridge to prevent them from freezing.

The Fluoride & Arsenic filter elements (PF-2) only last one year. “A short time” therefore means: the next use within the year. Keep in mind that the longer the elements are not in use, the more their ability to filter Fluoride & Arsenic may decrease. It is also wise to prime them every 2 weeks while they are being stored, to keep the storage process going.

If you have stored them in the fridge, we recommend priming the Berkey Fluoride & Arsenic filter elements (PF-2) again before you use them again. Do this for a maximum of 1 minute each in both directions.

The Berkey Fluoride & Arsenic filter elements (PF-2) must not be air-dried, because this can cause some bacterial growth in the filters.

If you have never used the elements:

If the elements are unopened and in their original packaging, make sure you do not store the elements in a room with a strong smell, such as a laundry room or garage. The elements contain carbon as one of their components, so it is possible that they absorb the smells of the room in which they are stored. If they are stored in a laundry room, for example, they may pick up the smell of strongly scented items such as washing powder.

If you have used your elements:

The way to store them depends on how long the Black Berkey filter elements will not be used:

If the filters will not be used for 4 to 15 days and you want to avoid priming again, remove the filters from the water filter, put them in a sealable bag or container and place the filters at the front of the fridge to prevent freezing. This keeps the filters largely saturated (wet), so that priming again is usually not necessary. If, for whatever reason, the filters work more slowly than normal, prime them again until the outer wall of the filter starts to sweat water droplets for 10 seconds.

For long-term storage we recommend drying the filters and storing them closed. It is important that they are bone dry before being stored for the long term, to prevent possible bacterial growth. One way to dry your filters is to leave them on a windowsill for one to three days and let them air dry. We also offer a tool that helps with both priming and drying (purging). It is the Black Berkey Primer. The advantage of drying (purging) the Black Berkey filter elements with the Black Berkey Primer is that they dry very quickly. Once the filters are bone dry, put them in a storage bag such as a large, sealable bag. The elements are extremely powerful and can absorb odours and smoke from the air. By sealing them in a bag, they cannot pick up any smells from the air. When you are ready to use the filters again, clean them by scrubbing the outside with a scouring sponge or a stiff brush. Then prime the filters again, either manually or with the Black Berkey Primer, before you put them back in the water filter.

In theory, the shelf life of the Black Berkey filter elements is unlimited.

**Please note that the storage methods above only apply to the Black Berkey filter elements.

If you have never used the elements:

If the elements are unopened and still in their original packaging, make sure you do not store the elements in a room with strong smells (such as a laundry room or garage). The elements contain carbon as one of their components, so it is possible that they absorb the smells of the room in which they are stored. If they are stored in a laundry room, for example, they may pick up the smell of strongly scented items such as washing powder.

** If you also store the upper and lower chambers of your Berkey system, it is best to empty both chambers before storing them. Water that stands still for a long time promotes the growth and production of bacteria. We recommend washing your Berkey system with soapy water before letting it dry.

Black Berkey filter elements do not necessarily need to be cleaned every time you clean the housing of the Berkey water filter (lower and upper chamber). This can vary, however, depending on the area and water source. In certain areas of the world the water is much dirtier than in others, and the elements will need to be cleaned more often; possibly even more often than the rest of the system requires. If your water is muddy or very dirty, we recommend pre-filtering the water by passing it through a kind of cloth, e.g. a shirt, sheet, bandana, etc., before you fill the Berkey water filter with it. Although this is not necessary, it keeps the cleaning schedule for the elements low by catching dirt that can clog the pores of your Black Berkey filter elements.

When is it time to clean your filters?

• The elements should be cleaned when you experience a drastic reduction in flow rate.
• You can also consider cleaning the elements periodically. For example every 6 months (NOTE!! Never more often than once every 6 months if you do not experience a reduction in flow rate). The advantage of this is that you will not experience a slow flow rate. Cleaning elements on a regular schedule is at your own discretion. This is a suggestion, not an obligation.

How do you clean the filters?

1. Empty your Berkey water filter and take out the Black Berkey filter elements.
2. Use a scouring sponge or a stiff brush and gently scrub the outside of the Black Berkey filter elements under cold running water.
3. Prime the filters again. If you are not familiar with this process, watch our instruction videos.
4. Fit the Black Berkey filter elements back into the Berkey water filter.
5. Finally, fill your Berkey water filter and, if you wish, carry out a red dye test as described in the instruction videos, to make sure the Black Berkey filter elements are still effective.

A TDS meter does not measure much change between unfiltered water and water filtered with a Berkey. This is normal, and the answer has to do with what a TDS meter actually measures. According to tdsmeter.com, “Total Dissolved Solids (TDS) is the total amount of mobile charged ions, including minerals, salts or metals dissolved in a given volume of water, expressed in units of mg per unit volume of water (mg/L), also referred to as parts per million (ppm). TDS is directly related to the purity of water and the quality of water purification systems and affects everything that consumes, lives in, or uses water, whether organic or inorganic, whether for better or for worse.”

This statement is both correct and incorrect. It is correct about what a TDS measurement consists of, namely the “total amount of mobile charged ions, including minerals, salts or metals dissolved in a given volume of water”. It is incorrect in its conclusion that TDS is related to the purity of the water and the quality of the water purification system. If the measure of a water purification system were how close it could bring the water to pure H2O, then it might be right. But people need minerals to live. So beneficial minerals in your water are actually a good thing. A high-quality water purification system should filter out things that are harmful to your body, but leave the beneficial things such as minerals behind. Black Berkey filter elements are designed to leave healthy and beneficial minerals in the water and to extract the unwanted heavy metals such as lead and mercury, as well as sedimentary minerals such as iron oxide and aluminium.

So if you use a TDS meter, you will find that the reading is about the same both before and after the water has passed through the Black Berkey filter elements. And that is correct. The Black Berkey filter elements retain all beneficial minerals. So, of the things a TDS meter will actually detect, the Black Berkey filter elements will only remove the unwanted heavy metals such as lead and mercury, as well as sedimentary minerals such as iron oxide and aluminium. That is why the TDS value will not change much, unless you have a significant amount of heavy metals or sedimentary minerals in your water.

A TDS meter does not measure the amount of biological and chemical contaminants (including, for example, chemicals, medicines, hormones, many pesticides and their residues, bacteria and viruses). Most importantly, do not rely on a TDS meter alone to judge whether your water is good. You can have water with a low TDS level that contains harmful bacteria. You can have water with a high TDS value that is completely safe (e.g. pure, uncontaminated sea salt water, although you would not drink it, but that is only because the mineral is salt). So make sure you know what a TDS meter actually measures.

The Black Berkey filters are made from a patented blend of different components, including high-grade carbonised coconut shell, for example. Berkey Water Systems confirms that there is no graphene oxide in the composition of the filter elements.

Moreover, Berkey Water Systems has no test reports available that verify the reduction of graphene oxide by the Black Berkey filters. Without test results, they cannot claim that the filter elements are able to reduce/remove this contaminant.

IMPORTANT INFORMATION FIRST The red dye test is only intended to check that your Berkey water filter has been assembled correctly, so that no water comes through other than from the stems of the Black Berkey filter elements, and that the filters are not exhausted. Berkey Water Systems has no independent test results showing by what percentage the red food dye is filtered out. They therefore cannot officially claim that this contaminant is reduced. So if the instructions below are not followed and, for example, a higher concentration of red dye is added, it is likely that it will not be reduced by 100%. It is therefore important to follow the instructions below carefully, in particular the amount of red dye and performing the test no more than twice a year.

The Black Berkey filter elements are powerful enough to remove red food dye from water. By performing a red dye test you can be sure that your Berkey water filter system is working properly.

GUIDELINES

• We recommend performing this test on first use and every six months thereafter (after cleaning) to make sure the Black Berkey filter elements are working properly.
• The red dye test is intended only for the Black Berkey filter elements and NOT for other filter elements (such as the Fluoride & Arsenic filters), which do not filter out the dye. This test is also not recommended for the Sport Berkey drinking bottle.
• Make sure the dye is RED. Red food dye (unlike the other colours) contains no minerals, so the element recognises it as a contaminant. Also do not use a natural red dye (such as beetroot juice), as this is not recognised as a contaminant either. The aim is to use a synthetic red dye, so use the original red dye.
• The red dye test must be performed after the Black Berkey filter elements have been primed.

PERFORMING THE TEST

NOTE: watch our instruction videos for a video of the red dye test being performed.

1. Start with an empty water filter system (upper and lower chamber) and remove any fluoride filters (if installed).
2. Place only the upper chamber (with the Black Berkey filter elements installed) on glasses of similar size (so the stems of the filters stick out into the glass). This makes it easy to see straight away which filter passes and which fails the test.
3. In a separate jug, add 3 drops (= 0.15 ml) of dye per litre of water and mix (with one bottle of original red dyeyou can therefore perform a full test several times). Pour the red water into the upper chamber until the filters are fully submerged. Please note: Never pour red dye directly from the bottle onto the filters or into the upper chamber. Always mix the dye with water beforehand in a separate jug.
4. Let the water filter from the upper chamber into the glasses below. When the glasses are three-quarters full, pour out the remaining water from the upper reservoir. Please note: The glasses may fill at different speeds.
5. Check the water in each glass. It should be clear, without a pink or red tint. If the water in one of the glasses is red or has a pink tint, that specific filter may be defective or exhausted. See below.

IF RED COLOUR IS OBSERVED IN THE WATER, CHECK THE FOLLOWING:

1. Are the wing nuts tight enough? Do not tighten the wing nuts with tools; they should be tightened by hand until you feel resistance, which is sufficient. If the wing nuts are too tight, this can damage the thread of the stem and/or the grooves of the wing nut. This can affect the seal. If this has happened, please contact us.
2. Are you using natural red food dye or a dye of another colour? Only synthetic red food dye is recommended for this test.
3. Is the black ring of the Black Berkey filter elements also in the upper chamber, and is the wing nut on the underside tightened? If the black ring is on the outside of the lower chamber (that is, directly at the wing nut), this is not a proper seal. The test will therefore fail. Place the black ring on the inside of the upper chamber and perform the test again.
4. Do the blocking plugs seal the unused holes properly (if applicable)? Are the blocking plugs firmly installed so that the hole is really sealed? For blocking plugs with a bolt and nut, a sealing ring must be fitted on both sides (not on one side only). If the plugs leak, the test will fail. Install the blocking plugs more firmly and perform the test again.
5. Are you retesting a filter element that has failed? Then make sure you first rinse this filter element and prime it again before testing again. Also make sure that all the water is out of the lower chamber (or glass). If you use the lower chamber or a glass to collect water, first rinse it out thoroughly with clean water. Now you are ready to repeat the test.
6. If you have done all of the above and a filter element still fails the red dye test, please contact us. The Black Berkey filter elements have a two-year warranty (in periods). View the warranty terms.

NOTE: watch our instruction videos for a video of the red dye test being performed.

For all laboratory test results of the Berkey water filter: click here. You will be redirected to the manufacturer's knowledge base, where all results are gathered on one page. These are all the tests carried out with the Black Berkey filter elements, which are the filter elements of the Berkey water filter.

In addition, this page also contains the test report of the Berkey Fluoride & Arsenic (PF-2) filter elements.

The Environmental Working Group (EWG) tested 10 water filter systems for their ability to remove 25 individual per- and polyfluoroalkyl substances (better known as “PFAS”) from tap water. In EWG's tests, the Berkey water filter (fitted with Black Berkey filter elements) removed PFAS to non-detectable levels, which placed the system in the “Best overall” category.

The Berkey water filter was also praised for its large capacity compared with other water filters tested, and for its “exceptionally long filter life” (each pair of authentic Black Berkey filter elements can filter up to approximately 22,700 litres (11,350 litres each) of tap water before replacement is recommended). CBS News Philadelphia produced a news report about EWG's tests, in which the Berkey water filter is mentioned. You can watch it here. CBS Colorado also mentioned the Berkey water filter in a TV news segment about the EWG test, which you can watch here.

EWG's water filter test results were released a week after the United States Geological Survey (USGS) published its study showing that the drinking water of almost half of American households contains at least one type of PFAS. PFAS have been in use since at least the 1950s and have been linked to a wide range of human health problems, including certain types of cancer and developmental, metabolic and immune disorders, and more. PFAS are called “forever chemicals” because they take a very long time to break down in the environment.

To protect yourself against PFAS in your drinking water, you should make sure you have a final barrier system. Think of a Berkey water filter fitted with the powerful Black Berkey filter elements, which have been independently tested by accredited laboratories to remove perfluorinated chemicals to below detectable levels.

Further reading: – EWG: News Release | Guide to PFAS Water Filters – CBS Colorado: Which Water Filters Can Block PFAs – CBS News Philadelphia: Environmental Group Tests to Find the Best Water Filters for Removing PFAS – New Study: “Forever Chemicals” Found in Nearly Half of U.S. Tap Water – Do Black Berkey® Elements Remove PFAS and Other PFCs in Drinking Water? – Black Berkey® Elements: The Final Barrier against PFOA and Other PFCs in Drinking Water

The lifespan of the filter varies depending on the source water and the degree of contamination. The recommendation for when the filter should be replaced depends on several factors. For filtering chlorine, for example, the filters last more than 45,000 litres per pair. However, there are several contaminants in the water, and the amount of each can differ.

The Black Berkey filters were therefore developed to last many years. However, we now live in a different time than a few years ago. The number of contaminants has only increased and they have become ever more severe (think of PFAS, or the considerable increase in medicine residues, pesticides, etc.). This has an enormous effect on the filters, which means they need to be replaced somewhat sooner. It is of course difficult to keep track of everything that is in the water and to what extent, which is why we advise replacing the Black Berkey filters after a maximum of 3 years when using tap water. If you use water from another source, the advice is to replace them sooner.

The Fluoride and Arsenic filters (PF-2) last a maximum of 3,700 litres of water or 1 year, whichever comes first. It is of course very difficult to keep track of the number of litres, so we advise going by one year.

The Coldstream FTO PLUS filter elements are easy to install, use and clean. Priming is not necessary and no additional filters are needed to remove fluoride. Before installing, simply rinse the outside under the cold tap and, if necessary, lightly scour it with a scouring sponge so that all production dust is removed.

Installation Follow the step-by-step instructions below:

• 1. Take the filter element and place the rubber ring on the stem.
• 2. Push the stem through a hole in the upper chamber.
• 3. Screw the wing nut onto the underside of the upper chamber. When you feel resistance, that is enough. PLEASE NOTE! Do not overtighten. Repeat steps 1 and 2 for any other filter elements.
• 4. Seal any remaining holes with blocking plugs.
• 5. Place the upper chamber on the lower chamber.
• 6. Fill the upper chamber with water and let the water run through. We recommend that you discard the first 2 cycles!

You can also always view a manual, see Manuals Coldstream FTO PLUS filters.

When transporting your system, we recommend detaching the filters. Let them dry and then roll them in a terry towel. Next, place them in the stainless steel or plastic housing and make sure they are secure (use extra towels if necessary) to prevent them from shifting or breaking.

We recommend cleaning the Coldstream FTO PLUS filter elements once a month, along with the containers and other parts of your water filter. However, if you notice a change in the taste/smell of the water earlier and/or a slower flow rate, this may indicate that your filters need cleaning.

Cleaning PLEASE NOTE! Do NOT use soap when cleaning a filter element. Make sure NO water gets into the stem of the filter element.

It is important that no water gets into the blue stem of the filter element. So hold the filter element by its base and keep it under cold running water for about 2 minutes. While water runs continuously over the filter element, lightly scrub the white ceramic exterior with a scouring sponge. Rinse thoroughly and set aside until it is ready to be installed again.

Remove the Coldstream FTO PLUS filters from your system and let them air dry. Wrap the filters in a terry towel and store them in a cool, dry place.

Lifespan: 1,500 litres or 6 months, whichever comes first. Of course it is difficult to keep track of the number of litres, so we always advise simply sticking to the 6 months. It makes no difference how many Coldstream FTO PLUS filter elements you use: all of them must be replaced after 6 months.

If during those 6 months you notice a change in the taste/smell of the water and/or a slower flow rate, this may indicate that your filters need cleaning. If after cleaning the flow rate does not increase or you still notice the same taste/smell, it is time to replace the filter elements.