Total Hardness

Total hardness is the sum of the calcium and magnesium concentrations, both expressed as calcium carbonate, in milligrams per liter (mg/L). You can determine your water’s hardness based on these concentrations of calcium carbonate:

High levels of calcium in drinking water mean you have “hard water.” Hard water can cause laundered clothes to look dingy. Hard water also causes a whitish-gray scale to form on glass shower doors and bathroom and kitchen fixtures.

Hard water can also be a nuisance at home because of:

• Gray staining of washed clothes
• Scum on wash and bath water after using soap or detergent
• Reduced lathering of soaps
• Buildup of scale on heating elements and boilers
• Reduced water flow in hot water distribution pipes due to scale buildup
• Accumulation of whitish-gray scale in tea kettles and other containers used to boil water

Hardness minerals can be removed with a water softener, which replaces the calcium and magnesium (and iron, manganese, radium and other positive ions) with sodium. High levels of sodium in drinking water may harm your health.