API Rena Bio Chem Stars are the best bio-filtration media available on the market today. The package of 10 from Aquarium Pharmaceuticals Filstar has the optimal pore size for spawning extremely large colonies of the beneficial bacteria to help the natural biological filter in the aquarium. The advanced polymer material allows for the maximum surface area.
1″ Tall x 1″ Wide (2″ Diameter).
Provides more surface area for bacterial colonization
Removes toxic ammonia and nitrites
Never needs replacing