SUPER RUST & SCALE POWERFUL SCALE & STAIN PREVENTER! This concentrated formula prevents ugly stains, scaling, and brown water. It will actually lighten some existing stains. A must for areas with well water or excessive metal and mineral problems. Start-up dosage: 15 oz. per 15,000 gallons. Maintenance dosage: 5 oz. per 15,000 gallons. Buy 4 quarts and SAVE!