Bio-Dex Aquadex 50 Stain-OffThe Bio Dex Aquadex 50 Stain Off is a powerful aid in the removal of metal stains and scales such as copper, iron, and cobalt that have accumulated in both pools and spas. This concentrated liquid is stable at high temperatures and is unaffected by chlorine, acids, or other sanitizing chemicals. Removes copper and iron stains from plaster pools Removes black cobalt stains from fiberglass pools and spas Prevents most of the toughest metal stains from