The removal of divalent cations by precipitation or ion exchange.

The removal of calcium and magnesium from water to reduce hardness.

the process of removing hardness (calcium and magnesium) from drinking water; done by chemical addition in municipal supplied and by ion exchange in homes.

Water softeners condition the water through an in exchange process. In other words, a softener exchanges sodium ions for calcium and magnesium ions. Softeners are sometimes confused with filtration, but are primarily used to reduce the mineral content (hardness) in water to prevent scale buildup. They do not produce "ingredient" water, free of off-tastes and odors, particulates, certain other contaminants and cysts.

Exchange of the hardness-forming cations (Ca2+ and Mg2+ ions) for sodium ions. This process involves changing the chemical constituents of the water. It is not a purification process.

The act of reducing scale-forming calcium and magnesium impurities from water.