The WATER SOFTENERS are a type of filtering appliance that removes calcium and magnesium from the water. Underground water supplies become hard because of the nature of the rock through which rainwater percolates as it filters down from the surface. The softener removes minerals that create water hardness, one of the most common water quality problems a homeowner encounters. Hard water destroys appliances, leaves filmy soap scum across bathrooms and kitchens, and dries out hair and skin. Water softening is the removal of calcium, magnesium, and certain other metal cations in hard water. The WATER SOFTENERS are available in various types.