I am also interested in a correct response as I intend on FOWL. Currently I am running Fluval 405 canister with carbon on bottom tray-rock ruble in the next two trays-and polishing pads on top. I also have a Bio-wheel on top of the tank.
From what I've read and the advice given to me.. If you're running a FOWLR then a canister filter is fine but it needs to be cleaned every 3 months or less depending on the amount of fish waste. As for your fluval I don't how the water flows in that one but from what I've read you want the water to hit some filter floss first in order to catch large particles (If you put carbon before the floss it'll waste quicker), then your rubble rock/bioballs/ceramic/etc (whatever you decide to use) a pad or floss, carbon and then another pad. If you have corals then just use it with carbon and that's it, but you're better off selling the canister and getting a reactor.