05 March 2019

Why does my water softener need salt?

The purpose of a water softener is to transform hard water into soft water. Salt is used to clean resin beads, to remove hardness from water.

The resin beads are found in the resin tank in the softener and have sodium ions electrostatically attached to them. The water softener pumps hard water through the resin beads and the hardness ions are exchanged with the sodium ions.  That is, the hardness ions will stick to the resin and displace the sodium ions which then end up in the softened water. 

Over time the resin fills up with hardness ions and can no longer soften the water. At that point the water softener must regenerate.  Salt brine from the brine tank is pumped into the resin and that salt brine washes away the hardness ions and replaces them with a fresh layer of sodium ions.  The softener resumes softening more water.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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