Ok I have a 75 right now I could use. But it holds some angels and a rainbow shark could I have them in the +240 or would they get eaten. Thanks
SimonL;4986024; said:A sump is (usually) a small tank that goes under your big one. It acts as a filter, as well as often holding equipment like heaters. In order to get a sump, you need to have the tank drilled, where they put a hole in the side. You fit a bulkhead and overflow box to the hole. Water drains from the tank into the sump, then is returned by a pump. The trick is you need a big enough sump to hold the draining water from the main tank when the pumps are off. I'd say a 75 gal minimum.