I have actually been thinking about doing something like this. I have a 375G 96x36x25 with two bulk heads on the bottom about a foot and half apart. I took pvc two elbows and a straight pipe and I cut slits into the straight pipe to drain. Both of these flow into separate 1" tubing which then are joined together at a Y which then flow in to my fluval fx5. I didnt really want to run a separate canister that would have to go over the back of the tank as the tank has a 2" lip on it and it would look bad and would also give an access for my turtles to climb out. I was wondering if there is any way I could run two canisters in a series somehow. I also have one of the larger oceanic trickle filters that I am not even using at the moment that I have thought of somehow using with the fx5, but I am not sure how it should all flow. Any ideas advice??