hard water

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Related to Water hardness: water softener

hard wa·ter

water containing ions, such as Mg2+ and Ca2+, that form insoluble salts with fatty acids so that ordinary soap will not lather in it.

hard water

Etymology: AS, heard + waeter
water that contains certain cations, particularly calcium and magnesium, that precipitate with soap solutions. The term is generally applied to tap water, and the degree of hardness varies with the source and previous treatment.
Water with a high content of calcium and magnesium salts—e.g., carbonates and sulphates—which may interfere with certain lab tests

hard water

Water with a high content of calcium and magnesium salts–eg, carbonates and sulfates, which may interfere with certain lab tests. See Mineral water, Spring water; Cf Soft water.

hard wa·ter

(hahrd wawtĕr)
That containing ions, such as Mg2+ and Ca2+, which form insoluble salts with fatty acids so that ordinary soap will not lather in it.
References in periodicals archive ?
In this way, in 10 MT field, the amount of water hardness omission reached to almost %70(50 mg CaC[O.
By controlling water hardness, poultry processors may be able to improve the ability of processing water to remove bacteria from the skin of processed poultry.
According to a British study (11) focusing on variation in mortality from CVD based on the water hardness in 11 British cities between 1950 and 1960, water hardness increased in five cities and decreased in six cities.
9) There does not appear to be any convincing evidence that water hardness causes adverse health effect in human.
These results suggest that a simultaneous increase in water hardness and alkalinity, as warranted by the application of CaC[O.
A new modern hardness measurement without the use of indicators enables fully automatic adjustment of softener cycles to the specific raw water hardness.
Siemens also announces the new Ionpure VNX-HH electrodeionization (EDI) module, which represents a significant advancementin feed water hardness tolerance, to two parts per million (ppm) as CaCO3 - a hardness level that is four times the industry standard of 0.
We looked at a number of factors that cause bad hair," she said, naming humidity, wind/rain/sun, air pollution, number of beauty salons, water hardness and demographics.
Lemm and research assistant Frank Santana monitor water quality daily, checking for ammonia, nitrates, nitrites, pH, and water hardness.
The level of water utilities' phosphate dosing not only varies from region to region according to the local water hardness, but can change significantly from one day to the next.