Alfagrog Ref: 140 Description What is Alfagrog? Alfagrog is a porous foamed ceramic material, which is lightweight, strong and inert. It's high surface area makes it the natural choice for colonisation by micro organisms in biological filtration systems resulting in cleaner water. Benefits of Alfagrog over other filter media: Extremely high surface area Highly porous Inert, pH neutral Lightweight Available worldwide Economical