This Sequa-sol sequestering agent holds iron, manganese, copper and calcium in solution so they don't react with other elements in the water. It prevents staining, scale and rust on pool equipment, pipes and fittings. Provides fast and effective protection against pool staining and scaling. Its powerful formula holds minerals in solution even in chlorine, bromine and strong UV sunlight. Prevention of staining and scaling saves both time and money. Use Sequa-sol sequestering agent as part of weekly maintenance program. To remove existing stains, use stain magnet. Sequa-sol sequestering agent can be added to your pool water at any time. It is most important to use at pool opening or when filling pool for the first time. Compatible with chlorine, bromine, biguanide, ozone and salt water sanitizing systems. Applications for the best results, add Sequa-sol sequestering agent as you are filling the pool and allow to circulate overnight before adding additional chemicals and add 16-ounce per 10,000 gallons of water. If the water is extremely hard (over 200 ppm) or has high iron, copper or manganese content (over 0.1 Ppm), add 32-ounce per 10,000 gallons of water. Following initial treatment, add 4-ounce per 10,000 gallons once a week during the pool season.