We can use hard water before my textile dry processing. So we can treat the water use in these following method. If we want to use hard water in textile dye processing first off all we need to remove the hardness of water. There are two types of hardness : (a) Temporary hardness, (b) permanent hardness.

(a)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 

(b) Permanent Hardness :   

CaSO4 + Na2CO3 → CaCO3+ Na2SO4    

MgSO4 + Na2CO3 → MgCO3+ Na2SO4  

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