The Fluval foam sleeve insert is specially designed for the Fluval internal filters. It functions as an effective mechanical media to remove debris from the aquarium. Foam also encourages populations of beneficial bacteria which are important for proper biological balance in your aquarium.
(Note: Nitrifying bacteria require time to become established. Lack of nitrifying bacteria in a new set-up may result in the aquarium becoming cloudy. This normally clears as the bacteria become established.
Available in Fluval sizes1(four in pack), Fluval 2, 3 and 4(2 in pack)