Water hardness

Water hardness means a value that expresses the content of calcium and magnesium ions (coming from the presence of salts soluble in the water) as well as any heavy metals present in the water.

Generally, this term refers to total hardness; permanent hardness, on the other hand, expresses the quantity of cations left in solution after prolonged boiling, while temporary hardness, obtained by the difference between the previous hardnesses, basically expresses the quantity of hydrogen carbonates.