hard water

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Related to Water hardness: water softener

hard water

[′härd ¦wȯd·ər]
(chemistry)
Water that contains certain salts, such as those of calcium or magnesium, which form insoluble deposits in boilers and form precipitates with soap.

hard water

Water containing solutions of mineral salts (sulfates of calcium and magnesium, carbonates, and bicarbonates). Also see water softener.
References in periodicals archive ?
According to a study (3), "soft water, hard arteries" was the summary of its result after demonstrating the correlation between mortality from cardiovascular disease in males aged 45-64 years and water hardness in 163 largest cities of the USA.
33) multivariate analysis in a case control study of 120,852 men and women in Netherland, Leurs et al observed no relationship between tap water hardness and IHD mortality(hard vs.
Users can program the De'Longhi Magnifica Digital Super Automatic Machine, adjusting the temperature, water hardness, coffee strength and cup size.
The amount is determined by water hardness, soil level of dishes and cycle selection.
ScaleBlaster reduces water hardness while eliminating limescale--deposits that foul water pipes and downstream appliances and surfaces such as water heaters, laundry machines, HVAC systems, etc.
Women recognized that water from the piped (subsurface) supply was "hard" compared to canal water; in al-Garda, water hardness in the canal measured 210-280 rag/L, compared to 450 mg/L for water from the piped system.
APPLICATION: Guidelines for the values of pH, temperature, dosages, and water hardness can be used to help control sizing in paper mills.
A study in Finland matched water characteristics to statistics on almost 19,000 men who had suffered a heart attack, and found that for every one unit increase in water hardness, there was a corresponding one per cent fall in risk of attack.
A study in Finland matched water characteristics to statistics on almost 19,000 men who had suffered a heart attack and found that for every one unit increase in water hardness, there was a corresponding 1pc fall in the risk of an attack.
Several models are available and sizing is based on water hardness and pipe size.