According to ion-exchange principle,exchange Mg2+ and Ca2+ with Na+ so that the water hardness decreases to *0mg per liter. The system is composed of resin tank (salt shaker), the controller, and the centralized control valve (made by U.S. FlECK company) or multi-way valve (made by U.S. AUTOTROL company). Programmed to run and regenerate automatically. Adopting the siphon principle, inject salt automatically, and don’t need salt pump and other ancillary equipment.

2. High rejection ofMg2+ Ca2+ and SO**-.