Limescale at home and limescale in your filter: what is the difference and how do you keep your system clean?

What exactly is limescale?

Limescale 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.

Limescale in your gravity filter

A 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.

Maintenance versus replacement

It 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.

If 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.

How do you prevent too much limescale build-up?

You 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.

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.

Frequently asked questions

Does a water filter remove limescale from the water? No. 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.

How often should I clean my filter element? This 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.

Can I clean my filter with vinegar or citric acid? Acid 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.