A favorite among many aquarists, under gravel fish tank filters work by drawing in the water into the gravel substrate. The gravel helps clean the water by removing large particles and debris. The water is then propelled into slots or holes found in the substrate tray. Because the gravel also serves as a breeding ground for beneficial bacteria that can remove ammonia and nitrites, the tank water is also biologically filtered as it passes through the filter. The clean water is then pumped back into the tank through risers or tubes that are usually found in a corner of the aquarium.

Why use under gravel fish tank filters

Under gravel fish tank filters offer several benefits. One of these is that it also helps keep the water temperature consistent. Compared to other types of aquarium filters, this type of filter is budget-friendly and is easy and very cost-effective to maintain.