Fluval ClearMax is a science grade resin designed to adsorb phosphate, nitrite and nitrate*. Getting rid of these compounds produces crystal clear water, reduces odours, and creates ideal conditions for fish. It also helps reduce time spent on maintaining your aquarium. Key Features : *Chemical filter media *Traps phosphate, nitrite and nitrate *Creates crystal clear water and ideal conditions for fish and plants *Helps reduce overall aquarium maintenance time *Treats up to 300 L (80 US gal) *Convenient 3 x 100 g (3.52 oz) format *Ideal for use with most canister filters *For best results, replace every 4 weeks *For use in freshwater and saltwater* aquariums *Clearmax does not remove nitrates from saltwater applications