What is water Hardness





Generally bore water contains Calcium and Magnesium minerals, the total amount of Calcium and magnesium is called Hardness.  This hardness is measured in PPM (Parts Per Million) or mg per Liters (Milli Grams per Liter).

Water Hardness =  Calcium Minerals (Ca2+)  + Magnesium Minerals (Mg2+)

Sometimes, if you give water sample for testing, you may get report mentioning Ca and Mg in the report. Ca2+ as Ca and Mg2+ as Mg.

Actually Calcium & Magnesium hardness is the concentration of Ca and Mg  ions expressed as equivalent of calcium carbonate. Total water hardness expressed as equivalent of CaCO3 can be calculated with below formula.

Total Water Hardness as CaCO3 = (Ca2+) X 2.5  + (Mg2+ ) X 4.1

If you are using hard water to clean your hands with soap, you may have felt like there was film of residue left on your hands, this is because, Soap reacts with Calcium and Magnesium minerals to form “Soap Scum” in hard water. Using hard water, consumption of detergent  will be high to get things clean, be at your hands, hair, or washing machine.

Many industrial & domestic water users are concerned about the hardness of their water. Like greaser, Industrial Boilers or cooling tower.  When hard water is heated, solid deposits of calcium carbonate can form, it raise the cost of heating the water, lower the efficiency of electric water heaters,  so your consumption of electricity also increases.

Which is hard water, Soft water

0 – 60              PPM (or) mg per Liter is        SOFT WATER

61 – 120          PPM (or) mg per Liter is        Moderately Hard  WATER

121 – 180        PPM (or) mg per Liter is        HARD WATER

181  Above     PPM (or) mg per Liter is        Very Hard WATER



Water Softener

Water Softener is a cylindrical unit which contains ion exchange resin as media, by passing water through the media hard water becomes soft, ion exchange resin contains Na+  Ion on its beads, which are exchanged with Ca2+ and Mg2+ ions from the bore water.