BIO-DEX PHOS+DR 55 gal Drum Phosphate Remover MAX is the product to use to treat very high levels of phosphates. It works with all sanitizing systems, water chemistry and filter media. Swimmers can go into the water right after you use the product. Phosphate Remover Max helps maintain a phosphate-free pool throughout the year when used as part of maintenance routine. Feel confident using Phosphate Remover MAX because it is non-toxic and non-hazardous, so it won't adversely affect swimmers.