Don Vandervort, Head Homeboy, has written more than 30 DIY home improvement books, been a segment host on HGTV, served as MSN.com's home improvement expert and written countless magazine articles.
The standard whole house water softener works on the principle of ion exchange, termed “cation exchange.” It conditions hard water by substituting sodium chloride (salt) for hard minerals such as calcium, magnesium, and iron.
Inside a cation-exchange softener, the house water supply flows through plastic-like beads called “resin,” which are arranged in columns called “resin beds,” which reside in the “resin tank.” These beads attract the mineral ions of hard water while giving off sodium ions.
To periodically recharge the beads with sodium ions, they’re flushed with salt water (brine), a process that removes the hard mineral ions from the resin and discharges them as waste. Once excess sodium is rinsed away, the cycle begins again.
A typical water softener has a resin tank, resin bed, brine tank, and some type of control. The resin tank is a container for the resin bed. The beads that make up the resin bed are typically made from styrene and divinylbenzene. The brine tank is filled with the water and dissolved salt used for regenerating the resin beads. The unit’s flow and regeneration processes are handled by the control.
