Only decent one that will fit is the octo 1000 hob I will eventually get 2. Since I cannot plumb this tank without fighting water levels in the internal wet-to-dry, I will just get a couple reef octopuss hob's. Some of the inline ones are kind of crappy...I looked at other options. RIO has gone out of business and used to make the needle wheel pumps that powered the skimmer casing...which Advanced Aqua Tanks sold designed for the tank. I think the reef octopuss hob will perform much better though.