Aquarium Sponge Filter | Fine Pore

The weighted base sits flat on the substrate and stays anchored without suction cups that pop off curved glass or fail over time in low water levels. The fine pore foam is sized to match the biological load of each tank range — more foam volume in the larger sizes means more surface area for the beneficial bacteria colony that processes ammonia and nitrite between water changes. A flow tube is included with every size and is matched to that unit's foam volume for proper air-lift circulation. Connect any standard aquarium air pump to get running — air pump is sold separately and not included. Fine pore foam outperforms coarse sponge filters for biological filtration because it produces significantly more surface area per square inch for bacteria to colonize. This matters most in established tanks with a real bioload where water parameters need to stay stable between maintenance sessions. The foam is gentle enough that shrimp, fry, and bettas graze the surface throughout the day without any risk of being pulled into an intake — the primary reason most shrimp and fry keepers switch to sponge filtration in the first place. Use it as the sole filter in tanks within the rated size range or run it alongside a canister or hang-on-back unit as a dedicated biological filtration stage.