Extension Circular 505
WATER SOFTENING for the HOME
Harvey Wilke, School of Civil Engineering, and Ruth Hutcheson, Extension Home Management
HARD WATER is found in over 85 percent of the United States—in four out of five homes. Nearly all of Indiana is in the hard water area of this country. There is a definite need for an improved soft water supply in the home. The 1955 Agricultural Census for Indiana indicated 54 percent of Indiana farmers with electrically powered water pressure systems. As late as March 1961 only 13 percent of Indiana farms had softeners.
What Is Water Hardness?
Water is said to be hard when it has excessive soap-consuming properties. Most homemakers recognize hard water by the ring in the bathtub and the greasy, grayish curd formed in sinks or dishpans. Hard water contains dissolved mineral compounds of calcium and magnesium. The more the water contains, the “harder” the water
is. More soap is required in hard water because suds will not begin to form until the calcium and magnesium demand for soap has been overcome.
Hardness does not cause rust colored or black stains. These are discussed in Extension Circular 507, “Iron Water Control for the Home.” Hardness has no relation to odors in water.
How Is Hardness Measured?
The chemist identifies hard water by the minerals it contains. The calcium and magnesium causing hardness are reported as grains per gallon, parts per million (ppm) or milligrams per liter (mg/1), expressed as calcium carbonate. One grain of hardness is the equivalent of 1 grain of calcium carbonate in 1 gallon of water. Hardness reported as parts per million or milligrams per
operative Extension Service, PURDUE UNIVERSITY, in cooperation with the School of Civil Engineering, Lafayette, Indiana