Dual Sponge Filter - Large - (XY-2822) - up to 20 gallons

XY-2822 - Large - Dual Sponge Filter - provides both mechanical and biological filtration in aquariums up to 20 gallons. Simply install an airline into the unit and to an air pump to provide both aeration and filtration for your fish. Beneficial bacteria colonize the sponge providing bio-filtration to facilitate the nitrogen cycle. In addition, the sponge traps larger waste particles mechanically cleaning the water without trapping baby fish or shrimp. Shrimp and baby shrimp like to feed on the outside of the filter. They are useful for as breeding filter or as a secondary filter. They can also be used as a pre-filtration unit by fitting to an external or a top filter.