Water softener salt pellets are formulated for water with high iron content. In addtion to hard water, many homeowners struggle with iron in their water supply. Iron can be found in city water supplies and in private wells. Rust stains, where there has been water, are good indications that you have iron in your water supply. Iron FighterⓇ Water Softener Salt Pellets are specially formulated for water with high iron content. These 99.6% pure water softener salt pellets help prevent rust stains on laundry, fixtures, sinks and tubs. Virtually 10% water soluble, it also minimizes mushing, bridging and rust buildup in your water softener brine tank – helping to keep your water softener running smoothly. 40 lb bag. Recommended for most tyypes of water softeners, particularly in regions of high-iron water content.