Do you guys know a good filter for a 2.5g aquarium? I really want a 2.5g hospital tank, which I may be transfering to a 2.5g shrimp since I have another 2.5g I can use. I have all I need for the tank except for a good filter, so does anyone know a good filter for a 2.5g. I also have a 55/77 and 10 aqueon filters which I'm interested in building sponge on top of my current filters in order to keep any fry born in those tanks from being sucked in especially the 55 which is going to be turned into a guppy tank which means many babies will be born. That means I need to get sponge on the filter to make it work. Thanks ahead. I am interested in not getting a seperate sponge filter but adding sponge on the current filter.