hard water


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Related to hard water: water softener

hard water

- That which contains large amounts of minerals.
See also related terms for minerals.

Hard water

Water that contains an appreciable amount of dissolved salts of calcium and magnesium. Such salts interfere with the action of soap. In the early days of the twentieth century, most rural water came from wells, and most of it was hard. Indeed, in some places, it was reputed to be so hard that a rock dropped into the well would bounce when it hit the water. Slight amounts of dissolved material in drinking water were often preferred because of the taste, but soft water was preferred for washing hair and clothes.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.hard water - water that contains mineral salts (as calcium and magnesium ions) that limit the formation of lather with soap
H2O, water - binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent
soft water - water that is not hard (does not contain mineral salts that interfere with the formation of lather with soap)
References in periodicals archive ?
They found that infants in areas with hard water were 87% more likely to have eczema.
Hard water contains high levels of calcium and magnesium ions that bind to surfactants such as sodium lauryl sulfate (SLS) and sodium lauryl ether sulfate (SLES) - which act as detergents or wetting agents - making them insoluble, so they precipitate onto the skin.
In regions where there is hard water, the surfactants in soap, such as sodium dodecyl sulfate, react with the calcium and magnesium ions in hard water, resulting in precipitation of the surfactant--leaving a film of residue on the skin, shower tiles, pipes, glassware, etc.
Hard water and geography should be considered as a possible factor when assessing patients with recalcitrant eczema, pruritus, or xerosis that cannot otherwise be reversed.
The textile dyes for cellulosic fibres are designed to have low solubility in water and these become very difficult to dissolve in very hard water because calcium and magnesium ions reduce the solubility of anionic dyes causing them to aggregate or even precipitate onto the fibre [4].
The experimental group was treated with hard water of district Kohat for 10 minutes on alternate days, for 3 months.
Generally, pH, alkalinity, hardness, chloride, and carbon dioxide increased from very soft water to the hard water with only two exceptions (alkalinity in soft water and chloride in hard water; Table I).
Hard water is rough on towels and clothes, leaves a residue on dishes and glasses, appears on bathroom glass and tile, causes spots on countertops and the minerals even build up in refrigerator filtration and ice making systems, essentially aging appliances.
Limescale build up is a particular problem in areas with hard water and mean appliances such as kettles need regular cleaning.
Letterkenny is split with one half receiving clean, pure water as others are left with discoloured, hard water.
Q: Our granite countertops get hard-water marks from the hard water we have.
Water softeners are commonly used in hard water areas to protect building services systems from limescale, however they can waste a considerable amount of water and also require a regular and costly supply of salt.