Bio air sponge internal filter for easy aquarium cleaning. The BOB internal sponge filter is equipped with a pump that draws in water. Its capacity is therefore larger than that of an air sponge filter. It has the significant advantage of filtering a larger volume of water and increasing the flow in the aquarium. Thanks to its fine sponge, this dual-sponge filter is completely safe, even for shrimp. It even removes small particles from the water. Additional and replacement sponges for the BOB sponge filter can be easily ordered and are available depending on stock.