Over time, scale formed from continuous contact with dissolved minerals in water can collect inside plumbing and on the internal parts of water-using appliances. Service calls to plumbers and repair persons may become necessary as water pressure drops and mechanical parts stop working. Hard water scale can also coat the inside of a water heater and drastically reduce its heating efficiency. Greater fuel consumption and higher utility bills result when the appliance has to heat water through a layer of rock. According to a study commissioned by the Water Quality Research Council and conducted at New Mexico State University, water heaters work 22-30 percent less efficiently with hard water, driving up utility bills unnecessarily.
Soft water is essentially free of dissolved calcium or magnesium.
A small percentage of homes are supplied with naturally soft water. But since naturally soft water usually has not been neutralized by passing through mineral layers in the ground, it can be quite corrosive. Softening water mechanically, such as with a home water softener, does not make it corrosive, however. Since calcium and magnesium are not present in soft water, no adverse reaction with soaps and detergents occurs. The result is the virtual elimination of soap scum and the corresponding reduction in time spent cleaning.