The ions of Calcium and Magnesium are responsible for the hardness of water where the concentration of certain minerals is what creates the “hardness” of water.
The hardness of water is developed due to the sufficiency of carbonates and Bi-Carbonates of Calcium and Magnesium.
There are no serious adverse health problems associated with drinking hard water But, hard water can contribute to dry skin and hair.
Generally, the hardness of water is measured by the means of TDS meter which measures the hardness on the basis of Electrical Conductivity of the Water.