My house is 10 1/2 years old. When we built it, the plumbers told us to clean our whirlpool tub jets with Automatic Dishwasher Detergent. We don't use the tub much, but now I've been trying repeatedly to clean it, and keep getting mold flakes when I turn it on. I've tried Clorox, Sanibath, something the pool stores suggest for spas (Purge), and nothing is getting it done. It's turned into a real problem. It seems clean, but when I test it a few days later, I get the flakes. I tried calling Hydrabath, the company our Home Owner's Manual referred us to, and they say they only sell the pump and have nothing to do with the tub itself. They suggested the Clorox. The installing plumbers seem to no longer be in business. Any ideas?