It you want to use hard water for my textile dye processing.then the hardness of water should be removed.The removing process is:

1.Temporary hardness: IS caused by calcium and/or magnesium hydrogen carbonate.These are formed as carbonate rain water passes over rocks containing carbonate ions,for example

H2O(I)+CO2(g)+CaCO3(s) →   Ca(HCO3)2(aq)

H2O(I)+CO2(g)+MgCO3(s)→Mg(HCO3)2(aq)

Temporary hardness can be removed simply by boiling the water.

2.Permanent hardness:Is caused by calcium and/or magnesium sulphate.These are formed as water passes over rocks containing sulphate ions,for example

aq.+CaSO4(s)→ Ca2+(aq)+SO42-(aq)

aq.+MgSO4(s)→Mg2(aq)+SO42-(aq)

Parmanent hardness cannot be removed by boiling but can often be removed by chemical treatment.....