By above, I take it you pump water from your sump into the fuge and then it gravity feeds down. That is how I do mine. My sump and fuge are in a separate room though.
*180 gal Display, 100 gal basement sump, 33 gal refugium, 3x250 MH, 2x160 VHO actinics, zoos, some softies, LPS & lots of acros and other SPS.
*100 gal prop tank plumbed into main system w/ 2x96 PC lights and 1x150 MH,