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.Fluval ClearMax+ chemical filter media+ traps phosphate, nitrite and nitrate+ creates crystal clear water, ideal conditions for fish and plants+ suitable for freshwater and marine water aquariums+ in marine water Nitrate is not removed+ Clearmax is active for approx. 4 week and should be exchanged after this time+ package content sufficient for 300 l water