Review on Aihotim Aquarium Sponge Filter Internal by Jessica Prive

We use this primarily for extra water purification in a 20 gallon aquarium. The included sponges and rocks have been tossed aside and replaced with a simple wad of filter floss. In general, the device works great, fulfills its functions and is easy to maintain. This particular filter was chosen for its small size and it hides really well in the back corner of the tank. Ultimately, the only real downside is the extremely thin and brittle plastic. We will definitely buy more when other tanks need a little more polish or when space constraints call for a small area filter.