Hard water is found in more than 85 percent of the United States, according to Virginia Cooperative Extension, making it the most common water quality problem.

Hard water occurs when excess calcium and magnesium are present, resulting in white/chalky deposits, dingy laundry, a decreased life of household plumbing, decreased efficiency of water heaters, dry skin, decreased suds and clogged pipes and shower heads.

Hard water is safe for drinking and cooking.

Think you might have hard water? It's easy to find out with a simple water test. Water testing kits can be purchased at home supply stores for about $30, but some water treatment businesses offer testing for free.

Hardness minerals are measured in grains per gallon of water or milligrams per liter. Less than 1.0 grains per gallon is soft; 3.5 to 7.0, moderately hard.

The most common way to treat hard water is through ion exchange water softening, a process in which the hardness ions, magnesium and calcium, are exchanged with either sodium or potassium ions.

When selecting a water softener, make sure the unit has sufficient water softening capacity for your family. A typical person uses 100 gallons of water per day.

For details, visit the Virginia Cooperative Extension's Web site, www.ext.vt.edu.