Im doing the same exact thing. Im building a stand for a 40 gal. I want to run it sump-less and just use an aqueon filter. I have some small fish, couple of clowns and maybe one of my mandarins I wanna move in there with as many zoas as I can fit. I have leds lighting my 90 so im gunna put those on the 40 and just put the old t-5 on my 90. good luck.