If I want to use hard water for my Textile dye processing then i need to remove the hardness of water before I use. There are two Ways:(1)Temporary hardness,(2) permanent hardness.

Temporary hardness:

1. Ca(HCO3)2 + Ca(OH)2 → 2CaCO3 ↓ +2H2O

2. Mg(HCO3)2 + 2Ca(OH)2 → 2MgCO3 +2H2O

     MgCO3 + Ca(OH)2 → Mg(OH)2 + CaCO3 

Permanent Hardness:   

CaSO4 + Na2CO3 → CaCO3+ Na2SO4    

       2. MgSO4 + Na2CO3 → MgCO3+ Na2SO4  

           MgCO3 + Ca(OH)2 → Mg(OH)2 + CaCO3