Sponge filters have been used in both freshwater and marine aquariums for decades. Designs vary, but these filters all use either passive or active water flow through a sponge-like material.
For optimal performance, a coarse open-cell foam is recommended for its ability to filter out particles and algae without clogging easily.
I have been using this type of filter, paired with high-throughput water pumps, in larger tank systems.
For smaller setups, cylindrical sponge filters [Lustar V] are a sensible option.
The media used in these filters is long-lasting and simple to clean, making them a cost-effective choice for purifying large volumes of aquarium water and holding a large load of fish.
I rely on sponge filtration in many tanks at my office in Atlanta to avoid having large amounts of organic detritus in the tank – regular wringing takes care of maintenance.
Of course, there are downsides to these filters as well; they take up space in the tank, and require frequent cleaning to remain safe and effective.
Sponge filters have been utilized for many years in a variety of designs. By actively or passively passing water through a sponge, coarse open cell foam can offer effective water clarification without clogging on micro particles or algae. This porous material does a commendable job in larger systems, when coupled with high throughput water pumps. For smaller systems, I typically install one or more cylindrical sponge filters [Lustar V], as their durable, non-expendable media makes them a cost-effective solution. In my Atlanta office, I am utilizing sponge filtration extensively, as I don’t have gravel installed in these tanks to capture organic particles. The benefit of these filters is their substantial volume of water they can purify, even when hosting a high-density load of fish. However, they do take up space within the tank and require regular cleaning to remain reliable and effective.