Installing a water softener on the water line to the water heater only provides the benefits of minimizing scale formation in the hot water system, lessens soap usage in bathing and laundering, and requires less salt to regenerate the softener resin than would be required to soften all water entering the home. Also, by not softening the cold water, one avoids the increased sodium content in cold water, which is primarily used for drinking, cooking, and other consumptive purposes.