Good-Bye Metal Sequester (Phosphate free) is a heavy duty chelating and sequestering agent that will not interfere with the function of a saltwater chlorine generator or add phosphorous to the pool. This product should be used in any pool that has a history of phosphate problems or as the product of choice when phosphates are actively tested for on a regular basis. Good-Bye Metal Sequester (Phosphate free) will chelate metals, surrounding them with a protective layer to prevent them from precipitating on surfaces and discoloring the water, while sequestering them into larger particles which can be removed by cartridge and DE style filters. Sand filters that utilize sand media will require the use of a filtration booster. Sand filters that utilize sand alternatives such as glass and zeolite materials may not require filtration boosters to remove the sequestered metals. Salt water compatible!