The hardness of a water is a measure of its calcium and magnesium ion content. It is distinguished in temporary hardness and permanent hardness. The first, also called carbonate hardness, represents the hardness associated with the presence of the bicarbonate ion and it disappears with boiling. The permanent hardness, on [...]

The water that is found in nature, that is the water that flows from the springs, which is extracted from the wells, which flows in the rivers and is located in the lakes and seas is never chemically and bacteriologically pure. Water always contains salts, gases and other impurities to [...]