Temporary and Permanent Hardness of Water

Temporary hardness is due to carbonate & bicarbonate anions present in water and also called carbonate hardness.
The temporary hardness is removed:

1. By boiling
2. By adding lime water (Ca(OH)2)

For example; CaCO3, MgCO3, Ca(HCO3)2, Mg(HCO3)2

Mainly permanent hardness is due to chloride & sulfate anions present in water and also called non-carbonate hardness. 

The Permanent Hardness can be removed:

1. By adding soda (Na2CO3)
2. By Permutit process (Sodium Zeolite)

For Example; CaCl2, MgCl2, CaSO4, MgSO4