Choosing the right size for your water softener

A typical 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 brine tank is filled with water and dissolved salt used for regenerating the resin beads. The unit's flow and regeneration processes are handled by the control.

Softeners are made in several sizes, rated by the number of grains of hardness they can handle between regenerations. Units rated from about 12,000 to 16,000 grains are considered small; medium-size units run from 20,000 to 40,000 grains; and large-capacity models can handle 40,000 grains or more.

You can figure the size of softener system your family needs by multiplying the number of people in your household by 75, the average number of gallons used per person per day. Take that and then multiply by the number of grains per gallon of hardness minerals present. The answer is the number of grains of hardness requiring removal each day. Compare this to the recharge cycle of the unit you're considering to see how frequently regeneration must occur. The idea is to get a unit that will go at least three days between recharges. Ideally, it can also handle times when you have guests or larger than normal water needs.