A water softener will improve the condition of your hair and skin, but there's a practical argument for the investment, too: Reducing the amount of calcium, iron or magnesium in your water can extend the lives of your water-using appliances.Hard water leaves mineral deposits behind when it flows, leaving stains near drains, spots on dishes, film on shower glass, scale on tubs and your clothes looking dingy. It will clog and shorten the lives of dishwashers, washers, water heaters, faucets and toilets, according to a 2010 Battelle Memorial Institute study that was commissioned by the Water Quality Research Foundation.