Kent Marine Poly Ox oxidizes harmful dissolved and suspended organic matter for easy filtration removal. It assists in preventing growth of various cyanobacteria (commonly called red or blue-green slime algae) by simply removing their food source. It will oxidize leftover food, and dissolved and suspended organic matter. This will increase the water quality and provide a better environment for your fish and invertebrates! For fresh or marine systems. Professional strength, no phosphate and nitrate. Shipping weight: 3/4 lbs.