"I bought this aqueon 5 gallon tank and it looks nice with a quiet hang-on filter and a light on the hood and it also have a feeding door on the hood.
The hood have a cut-off hole for an upgrade (outside hanging) filter but the bar that you hook the original filter is blocking the way, so that cut-off hole is for nothing. The only way you can upgrade the filter is if you saw off the bar that is blocking the way which is not so easy to do. The replacement cartridge for the filter is hard to find in local stores here in Hawaii. They carry a replacement cartridge on petsco. If you want to buy a space saving aquarium I would suggest that you look for something else. There is a serious design flaw on this one."