What is hard water?

http://www.ultraclean-cn.com/ 2006-9-27 10:57:27
[Brief] When water contains a significant amount of calcium and magnesium, it is called hard water. Hard water is known to clog pipes and to complicate soap and detergent dissolving in water...

When water is referred to as 'hard' this simply means, that it contains more minerals than ordinary water. These are especially the minerals calcium and magnesium. The degree of hardness of water increases when more calcium and magnesium dissolves.
Magnesium and calcium are positively charged ions. Because of their presence, other positively charged ions will dissolve less easily in hard water than in water that does not contain calcium and magnesium.
This is the cause of the fact that soap doesn't really dissolve in hard water.

 

Which industries attach value to hardness of water?
In many industrial applications, such as the drinking water preparation, in breweries and in sodas, but also for cooling- and boiler feed water the hardness of the water is very important.