While you don’t necessarily have to use salt, every water softener uses a cleaning agent of some kind–most use salt. A water softener can only “absorb” so many hardness ions; and after it has reached hardness saturation, it must regenerate (trade all the hard ions for soft ones to be able to soften more water). When the softener regenerates, it must use a solution of some kind to rinse away the hardness ions. Most commonly the solution is sodium saturated water (salt water). Alternatively a potassium solution can also be used to regenerate the resin. Perhaps you’ve heard of magnetic water treatment systems or catalytic converters. Marketers of these water treatment devices are very careful regarding what they say. Truly magnetic systems can change the chemical balance of the water and suspend hardness ions in the water. However, most neglect to mention is that even though the hardness ions have been suspended, they’re not removed from the water. If the hardness ions are not kept in the heavy magnetic field, the hardness ions resume their “hard” effect on the water. Magnetic water treatment units were developed by the U.S. Army as a cost effective way to eliminate the effects of hard water while the water travels through boilers (or other in-line water equipment)–and magnetic water treatment systems do exactly that: while the water’s in the boiler it’s soft, when it comes out again, it’s already rebalancing its chemical composition and becoming hard again. To maintain the effect of magnetic water treatment system, you would have to install strong magnetic polarity devices every few feet on your household pipes. Otherwise, the water passes through, becomes soft then “hardens” again in your pipes.