Ideal for biorb aquariumsalfagrog filter media has a very high surface area making it an ideal material on which micro organisms can adhere and boost biological decomposition of pollutants. Used to maximise the optimum media surface area with high water flow rates.the manufacturing process,which produces the ceramic media,ensures that no substances are present to adversely affect the health of fish or plants.alfagrog is ideal for the use in filtration systems,as aquatic gravel or aquarium landscaping.weight 2kgalfagrog is ideal for use in any biological filter system. It is very popular among koi keepers and commonly used in multi chamber filter systems.replacing plastic filter media with alfagrog will massively increase the biological capacity of your filter.check out our other items by clicking above