Some people love how hard water affects their hair. I can tell a big difference and I don't like it. I think it does cause frizz for me. I just wanna echo what Robin said, the only hard and fast rule is DON'T USE SOAP IN HARD WATER!!!

I always link this thread when someone asks about hard water. It may be overkill on info -- but crimson did a fantastic job. Everything you ever wanted to know about hard water heh.
Grand Goobah Caedran, Aqueous Infusion of Demulcents, Order of the Curly Crusaders

Fia 2cFi, fine texture, med porosity CG 5-29-09 * My hair loves protein! Currently using : DermOrganics Shampoo and IHM, G2B Kinkier Mousse, Re:Coil VMM, Anything Spiral Solutions! MO Sealing. Coconut Oil Pre-Poo, once a month Hard Water shampoo. Avoiding Glycerin in finishing products.