Originally used on commercial fish hatcheries, Tank Clear is a special filtration media which breeds ammonia, nitrite, and nitrate-eating bacteria in its microscopic voids and tunnels. Tank Clear's balance of external porosity and internal density ensures robust cultivation of the nitrifying and denitrifying bacteria required to complete the Nitrogen Cycle.

The surface of the Tank Clear media pellets provide living places for the aerobic bacteria of the first two stages of the Nitrogen Cycle - converting ammonia to nitrite and then nitrite into nitrate.

The center of the media pellets provide an anoxic/anaerobic environment for nitrate-eating bacteria to grow; the bacteria that live in this environment convert nitrate into harmless nitrogen gas, which is then expelled from the surface of the water.