Water Hardness Information
Water hardness refers to the concentration of minerals, primarily calcium and magnesium ions,
in water.
The hardness of water is usually measured in terms of calcium carbonate (CaCO₃) equivalents,
expressed in parts per million (ppm) or milligrams per liter (mg/L).
There are two types of water hardness:
Temporary Hardness:
Temporary hardness is caused by the presence of bicarbonate ions (HCO₃⁻) in water.
It can be removed by boiling the water, which causes the bicarbonate ions to decompose into carbonate
(CO₃²⁻) and carbon dioxide (CO₂).
The carbonate ions can then react with calcium and magnesium ions to form insoluble precipitates that
can be easily removed.
Permanent Hardness:
Permanent hardness is due to the presence of non-carbonate ions, such as sulfates and chlorides of
calcium and magnesium.
Unlike temporary hardness, it cannot be removed by boiling.
Water softening methods, such as ion exchange or the addition of certain chemicals, are used to reduce
permanent hardness.
Water hardness has several effects, including:
Scale Formation:
Hard water can lead to the buildup of scale deposits in pipes, appliances, and water heaters,
reducing their efficiency over time.
Soap Scum:
Hard water reacts with soap to form a sticky residue known as soap scum, which can be
challenging to rinse off.
Appliance Efficiency:
The accumulation of scale in appliances like water heaters and dishwashers can decrease their efficiency
and increase energy consumption.
Skin and Hair Issues:
Some people may experience dry skin and dull hair when exposed to hard water, as soap and shampoo
may not lather as effectively.