So this is an interesting question i have ponder since i got into the wet life. Can a canister filter be built that is large enough for a monster tank. I know i can get 58 gallon screw top barrels made of hdpe. I would use a reeflo dart/snapper or similar for flow, but for media. Do i just super size my media using foam block and lava rock? Has any one built one of these closed filter systems? I'd love to hear other's stories on their monster canisters as i plan mine. I'll try to draft up some plans on it and post with this.