Hard water is water that has high mineral content (in contrast with "soft water").
Hard drinking water is generally not harmful to one's health, but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers, and other equipment that handles water. In domestic settings, hard water is often indicated by a lack of suds formation when soap is agitated in water. Wherever water hardness is a concern, water softening is commonly used to reduce hard water's adverse effects.
Read more about Hard Water: Sources of Hardness, Effects of Hard Water, Measurement
Famous quotes containing the words hard and/or water:
“The Indian remarked as before, “Must have hard wood to cook moose-meat,” as if that were a maxim, and proceeded to get it. My companion cooked some in California fashion, winding a long string of the meat round a stick and slowly turning it in his hand before the fire. It was very good. But the Indian, not approving of the mode, or because he was not allowed to cook it his own way, would not taste it.”
—Henry David Thoreau (1817–1862)
“The history of persecution is a history of endeavors to cheat nature, to make water run up hill, to twist a rope of sand.”
—Ralph Waldo Emerson (1803–1882)