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 ?
Routee, In Water hardness salts, Encyclopedia of Textile Finishing.
Does water hardness have preventive effect on cardiovascular disease?
In this way, in 10 MT field, the amount of water hardness omission reached to almost %70(50 mg CaC[O.
Afterwards, water hardness is probably more important than water alkalinity in producing significant effects on fish growth.
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.
Likewise nutritional studies, experimental works on water hardness would also require calcium-free water and low-calcium water in order to correctly evaluate the effects of the different calcium materials on fish growth performance.
3) There is an increasing level of evidence that drinking water hardness which has elevated concentration of magnesium may reduce the risk of cardiac death, in particular the risk of sudden cardiac death.
Systems can range from point-of-use, such as those at a tap in the kitchen for drinking and cooking purposes, or for the whole house if water hardness is an issue.
Extensive investigations carried out by the UHB - which has maintained throughout that patient safety has not been compromised - concluded that a water hardness issue had caused the water marks and the problem was solved by switching to a different detergent.
Peter, 1974) indicates that water hardness plays role in heart diseases in human.