Water Softener Resin
Water softener resin or ion exchange resin are used to replace the magnesium and calcium ions found in hard water with sodium ions. Salt, or sodium chloride, rinses through the resin beads during the regeneration of the softener, and washes the hard water ions off of the resin beads replacing them with new sodium ions. Essentially this is the heart of your water softener and standard 8% resin will breakdown 2-10% each year.