Home water softeners use the ion-exchange process. When the sodium is depleted, no further hardness can be adsorbed. This removes calcium and magnesium and replaces sodium on the exchange sites so more water can be softened. Finally, the media is flushed to remove brine. Water meter control.
Regeneration begins when a set volume has been used.
This reduces unnecessary regeneration, but is insensitive to hardness changes and you may be without softened water unless you have a second media tank. Usually, meter controls are more expensive than time-clock controls and two tanks increase the cost. Hardness sensor control. Sensor detects hardness of the softened water and initiates regeneration when needed. This minimizes potential for unnecessary regeneration, but is usually the most expensive type of softener.