Definitioner
Noncarbonate Hardness
water hardness due to the presence of compounds such as calcium and magnesium chlorides, sulfates or nitrates, the excess of total hardness over total alkalinity.
Magnesium
one of the elements making up the earths crust, the compounds of which when dis-solved in water make the water hard. The presence of magnesium in water is a factor contributing to the formation of scale and insoluble soap curds.
Hardness
a characteristic of natural water due to the presence of dissolved calcium and magnesium; water hardness is responsible for most scale formation in pipes and water heaters, and forms insoluble" curd" when it reacts with soaps. Hardness is usually expressed in grains per gallon, parts per million, or milligrams per liter, all as calcium carbonate equivalent.
Calcium
one of the principal elements making up the earths crust, the compounds of which make the water hard. The presence of calcium in water is a factor contributing to the formation of scale and insoluble soap curds which are a means of clearly identifying hard water.