hard water

(redirected from Hardness of water)
Also found in: Dictionary, Thesaurus, Encyclopedia.

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.
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 ?
It is noteworthy that the calcium hardness of water increased close to 500 mg [L.sup.-1] CaC[O.sub.3] in the present work, more than three times higher than the upper suitable limit for aquaculture (BOYD; TUCKER, 1998).
So, the hardness of water may be one of the characteristics of processing water that should be monitored by poultry processors.
The hardness of water for commercially available drinking water samples varied from very soft to hard (2.61 mg/l to 169.13 mg/l).
Boiler water treatment formulation can be made from these dyes to remove hardness of water. Similarly, during application of dyes on fibers, EDTA, NTA and Calgon are added as sequestrants, while using these dyes these chemicals will not be added.
The Total Hardness of water is due to presence of cations, [Ca.sup.2+], [Mg.sup.2+], [Fe.sup.2+], [Mn.sup.2+] and anions, HC[O3.sup.-], S[O4.sup.2-], [Cl.sup.-].
CORRELATIONS BETWEEN CALCIUM, MAGNESIUM AND HARDNESS OF WATER IN THE DRINKING WATERS OF DECATUR COUNTY GEORGIA AND THE INCIDENCE OF CARDIOVASCULAR AND CEREBROVASCULAR DISEASES, Abe A.
Severn Trent's price hike, announced last night, also includes pounds 15 million for tackling nitrates in Warwickshire's water, pounds 19 million improving the taste, odour and hardness of water in the county, pounds 4.5 million on sewer flooding, and pounds 30 million on renewing and maintaining water mains in the county.
Hardness of water is caused by the presence of multivalent metallic cations and is largely due to calcium, Ca++, and magnesium, Mg++ ions.
Hardness of water may be due to high amounts of Ca, Mg and Fe.
First two salts are the source of temporary hardness of water and the last two cause the permanent hardness of water.