a class of chemical compounds that reacts with minerals (heavy metals) such as iron, copper, manganese and calcium and forms stable, soluble products. This action helps prevent staining and discoloration and is the preferred method for treating iron, copper and manganese. When treating iron, manganese or copper, chelates should be added at a level at least equal to, if not greater than, the mineral being treated. Chelation is a one molecule vs. one molecule process. Adding more chelating agent is usually better than adding less.