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:
“She whom I love is hard to catch and conquer,
Hard, but O the glory of the winning were she won!”
—George Meredith (1828–1909)
“A man’s social and spiritual discipline must answer to his corporeal. He must lean on a friend who has a hard breast, as he would lie on a hard bed. He must drink cold water for his only beverage. So he must not hear sweetened and colored words, but pure and refreshing truths. He must daily bathe in truth cold as spring water, not warmed by the sympathy of friends.”
—Henry David Thoreau (1817–1862)