Applied Biochemists StainTrine stain remover has a fast-acting formula that performs two jobs in one. It removes stains already in your pool and prevents new ones from forming. StainTrine quickly removes or lightens existing stain and scale while protecting your equipment with chelating agents. The best part is that you can swim immediately after application! Features include fast removal of most stains, a professional strength formula, and no testing is required. Staintrine's formula prevents colored water and scale buildup on filters, pumps, and piping. To use apply 16 oz per 10,000 gallons of pool water as close to the affected area as possible. Staintrine is compatible with chlorine, bromin, biaguanide and salt water sanitizing systems. Check out PoguePoolSpa.com for more Applied Biochemists chemicals.