Hard Water

• Hard water contains dissolved calcium and magnesium that prevent detergents from dissolving completely. Not only is more soap required, but some of the undissolved soap collects on dishware and clothing. The minerals themselves can also form deposits in pipes and appliances.
  
  

Mineral Removal

• A water softener removes dissolved minerals by passing the water through tightly packed polystyrene beads where the positively charged metal ions are attracted and collected.
  
  

Recharging

• Periodically a brine solution passes through the beads and its sodium ions displace those collected from the water. The newly formed metal chlorides are discharged down the drain.
  
  

Controls and Power

• The softener controller can be as simple as a mechanical timer to perform recharge operations on a preset schedule, or it may contain a water usage monitor to determine when the beads are saturated. Electrical power is needed for operating most controls and their valves, but some softeners use water pressure to do this work.
  
  

Health issues

• The introduction of sodium into the conditioned water may be detrimental to people with high blood pressure. If so, a line can be added to bypass the softener and deliver hard water for drinking. To eliminate the sodium, potassium chloride may be used instead of common salt to recharge the system.