Leisure Time Filter CleanLeisure Time Filter Clean is a concentrated formula that quickly and effectively cleans your cartridge, sand, or DE filters of any scale, grease, oils, or impacted dirt, restoring them to optimal efficiency. Simply apply Filter Clean to your filter and let it work overnight. That's it! Even the worst contaminants will be removed. Best of all, Filter Clean is compatible with chlorine, bromine, and biguanide sanitizers, giving you no reason not to