Hard water? Sounds like an oxymoron, doesn’t it? But hard water is simply water with a high mineral content. Usually there are higher levels of calcium and magnesium, along with trace amounts of bicarbonates and sulfates. According to the United States Geological Survey, an estimated 89.3% of American homes have hard water.
While hard water isn’t harmful to humans, it can cause some unpleasant effects. The minerals in hard water can make your coffee or tea taste bitter. These minerals can also cause a buildup of calcium or limescale in water pipes and faucets causing them to clog. Hardness also prevents soap from lathering up, making it difficult to rinse off. People who have hard water may experience a "less than clean" feeling, since the hardness will leave a soapy residue clinging to their bodies.