Hello All, I bought this 100 Gallon tank (25.5H x 20W x 48L) it was custom made with sump filter holes on the top and came with a fluval 405. However, I couldnt get the fluval 405 to work (not sure why, tried nearly for an hour or two). I took my filter from a 56 Gallon tank (AquaTop CF-400UV Cannister stated 370GPH) and put in the 100 Gallon. I know this isnt enough filtration, but I was thinking of getting another CF-400UV, would that work? I am not adding any more fish until late summer. Transfered from 56 Gallon to 100 Gallon: All plants,driftwood, and clay pots. I will not be using the sump filtration device because of the possibility of leaking and if the power runs out then I'm screwed. During last summer we had rolling brown outs in my area.