4 Pounds (1.9 Kilo) Alfagrog Filter Media. Alfagrog is a very porous biological filter media that has a large surface area for bacteria to congregate in and clean your pond or aquarium water. Alfagrog is a porous foamed ceramic material, which is lightweight, strong and inert. It’s high surface area makes it the natural choice for colonization by micro organisms in biological filtration systems resulting in cleaner water. Selected clays and raw materials are sintered at a high temperature to produce a foamed ceramic porous mass, which is crushed and sieved to a convenient particle size. Alfagrog can also be used as decorative aquatic gravel, aquarium landscaping and in a wide variety of applications. Larger size pieces can be used as a substitute for live rock.
Benefits of Alfagrog over other filter media:
Extremely high surface area
Inert, pH neutral