The hardness of water is mainly composed of cations: calcium (Ca2+) magnesium (Mg2+) ions. When the raw water containing hardness passes through the resin layer of the exchanger, the calcium and magnesium ions in the water are adsorbed by the resin, and sodium ions are released at the same time.

In this way, the water flowing out of the exchanger is softened water with the hardness ions removed. When the resin adsorbing calcium and magnesium ions.