Grain capacity refers to how many grains of water hardness the water softener can remove before it reaches its capacity. Water softeners work by using beads with negative charges to attract calcium and magnesium with positive charges. At some point, the beads become saturated and can no longer function. Grain capacity refers to that point. Water Boss offers two models with 22,000-grain capacity and one model with 36,400-grain capacity. Whirlpool through its licensed partner Ecodyne Water Systems offers four models with grain capacity ranging from a low of 20,000 to a high of 48,000.
Regeneration is the process that refreshes the beads once they become saturated. The purpose is to restore them to their original condition so they can continue to remove calcium and magnesium. Sodium in a solution replaces the calcium and magnesium on the beads and the two minerals are washed away. The Water Boss models take anywhere from 18 to 21 minutes to regenerate. Whirlpool offers a Demand Initiated Regeneration system that monitors water usage and only regenerates as needed as opposed to a fixed schedule.
Water softeners use salt in the regeneration phase. Two of the Water Boss models use 2.5 pounds of salt and the other model uses 3 pounds for regeneration. The total monthly use of salt depends upon the number of times the system regenerates. Water usage determines regeneration; the more water you use the more often the system regenerates. Whirlpool promotes its salt-saving technology and estimates its units use between 20 and 80 pounds of salt per month.
Water softeners use water in the regeneration phase to wash away the minerals. Water Boss has one model that uses 12 gallons and two models that use 14 gallons. Whirlpool states that it takes the same amount of water as one load of laundry.