Review on Aquapapa 4X Bio Sponge Filter: Ideal Betta Fry Aquarium Solution for Tanks up to 15 Gal by April Nelson

Nice that there are several foam filters included with the purchase to use in the future if needed. The suction on them doesn't actually keep the sponge in the water, even after the sponge is filled with water. The sponge keeps floating and the suction cups don't hold the device in place. The end result is a sponge filter that partially floats on top and bubbles from the drain cause water to slosh slightly out the top of the tank. There is a hole at the top of my aquarium. When I sit next to it, a tiny amount of water always splashes on my head or hands.