You often ask the question, what exactly is water hardness? That’s why we come out to meet you! Water hardness is a measure of the concentration of calcium and magnesium ions. That is, if these ions are present – the water is hard. In order to soften the water, they need to be removed or replaced (e.g. with polyphosphate and KDF filters).

Waterhardness – how do the polyphosphate and KDF filters work, which can cancel it?

Polyphosphate

• does not remove calcium and magnesium, but binds them in the form of soluble chemical complexes.
• This prevents ions from forming deposits in the form of scale (calcium carbonate).
• the stone becomes amorphous and soft, making it easier to rinse off and not stick to the surface.

KDF

• consists of a mixture of copper and zinc.
• reduces chlorine, heavy metals and has an antibacterial effect.
• does not soften the water, but helps prevent scale build-up by modifying the structure of ions and deposits.

Activated carbon

• removes chlorine, odours and some organic pollutants.
• has no effect on water hardness or limescale build-up.

📌 Carbon, polyphosphate and KDF filters do not reduce the hardness of water, because they do not eliminate calcium and magnesium. However, by modifying their chemical or physical form, they prevent the formation of hard sediment, which tends to stick to fittings, tiles or skin. As a result, the user sees less limescale, although the water still contains the same amounts of ions responsible for hardness.

If you want to learn more about hard water , we also encourage you to read the article “Hard water, or what kind of water?”.