sera siporax is a fully biological filter material for all internal, external and trickle filter systems, and for garden pond filters.

1 liter sera siporax provides as much settling area for bacteria as approximately 34 liters of ceramic filter material. Therefore 1 liter sera siporax ensures more than 200 liters of biologically clean aquarium water. sera siporax is an excellent choice for small filters.
Prefilter with sera biofibres or sera filter wool to prevent large particles from entering the biofilter.
sera siporax provides anaerobic bacteria an extremely large amount of open-pored tunnel structures. This allows an ideal supply of the anaerobic bacteria with nutrients and a smallest amount of fresh water. There are oxygen-poor conditions within the tunnels. This makes the bacteria crack nitrate to get enough oxygen. Consequently, they continuously break down nitrate, and the aquarium water remains low in nitrate.
The surface of one liter of sera siporax has almost as much biological breakdown power as 34 liters of ceramic filter material.