Water purification generally means freeing water from any kind of impurity it contains, such as contaminants or micro organisms.Water purification is not a very one-sided process; the purification process contains many steps. The steps that need to be progressed depend on the kind of impurities that are found in the water. This can differ very much for different types of water.

Water quality is determined by the presence and quantity of contaminants, by physical/ chemical factors such as pH and conductivity, by the number of salts present and by the presence of nutrients. Humans largely influence all these factors, as they discharge their waste in water and add all kinds of substances and contaminants to water that are not naturally present.

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.
Water softening is a technique that serves the removal of the ions that cause the water to be hard, in most cases calcium and magnesium ions.
The best way to soften water is to use a water softener unit and connect it directly to the water supply.