The word “hardness” originally came from measuring water’s ability to make soapsuds. If water is hard, making a lather or suds for showering or washing clothes and dishes is “hard” to do. Hardness is caused by the calcium and magnesium ions that occur naturally in all water. The more calcium and magnesium, the greater the hardness.
Calcium and magnesium tend to settle out when the water is heated or it evaporates. This leaves the white deposits (calcium carbonate or CaCO3) on glassware, shower doors, in coffeepots, etc.
City of Yuma water contains 310 to 380 milligrams per liter or 18 to 22 grains per gallon of total hardness as CaCO3 (1.0 gpg = 17.1 mg/l).
Today, most detergents and cleaning agents counteract water hardness but many soaps do not. Commercial products such as Jet DryTM can be used in dishwashers to counteract the deposits left by hard water. Also, vinegar can be used in the final rinse of the dishwasher. Deposits can be removed from showerheads, coffeepots, etc. by soaking overnight in vinegar, then rinsing with water before use. If you don’t care for hard water, a water softener can be installed in your home.