Naturewater 10Inch - 254mm Resin-Filter Cartridge RS-10D

Inside the cartridge, high-quality resin is responsible for water softening.

Calcium ions and magnesium ions, which are the minerals causing water hardness, are bound and selectively exchanged for sodium ions. Unlike calcium or magnesium ions, sodium ions do not leave behind insoluble salt residues. The resin contained is a macroporous acidic cation exchanger.

A cation exchanger is an ion exchanger that can replace dissolved ions with other ions of the same charge (for calcium and magnesium: 2+). The ions to be exchanged are bound to the ion exchange material, which in turn releases an equivalent amount of previously bound ions into the solution. For example, a cation ion exchanger can exchange calcium cations dissolved in regular tap water for sodium cations bound to the ion exchanger. Such cation ion exchangers are also found in dishwashers. They prepare water for washing processes that is free of calcium cations, which would otherwise lead to the formation of limescale stains. When this cation exchanger is exhausted and fully saturated with calcium cations, it must be regenerated. This is done by displacing the bound calcium cations with a highly concentrated solution of sodium chloride (table salt). This process is referred to as the regeneration of an exchanger.