US Patent 7811971 Combination algae killer and surface stain remover

A stain removal formula includes a combination of a bromide donor, a salt of sulfamic acid; and a salt of phosphoric acid. Preferred formulas include effective amounts of sodium bromide, sodium sulfamic acid, sodium hexametaphosphate, disodium phosphate, and tetrasodium pyrophosphate. In a swimming pool, preferred formulas are effective in resolving algae stain within a 2 hour period, which represents at least an order of magnitude greater efficacy than prior art formulations. In addition, preferred formulas provide ongoing effectiveness in suppressing bacterial, fungal and/or algae growth.