So I've decided to keep the over abundance of frag racks out of my display. Currently I have a 72 gal rimless (36x18x20), I've purchased a 21g rimless RR deep blue micro frag tank, and i'm considering my options. It'll be barebottom with just black frag rack, maybe in a couple different heights. It will be lit either by a 150w current sunpod, or a chinese 3w bridgelux fixture. I'm considering plumbing it directly into my display tank, or just running a 40b with a skimmer and fuge. that's right. my sump will be twice the size of my frag tank. Any rock that i will add has been cured for a long time (6mos to a year). I may do a smaller fuge only sump, 20L, and have the tank drain into my sump, pump water through the fuge which will be under the frag tank. The fuge would have adequate sand(probably a DSB) live rock, and maybe some cheato for the frag tank. Any thoughts? I dont want to add bulk heads or do any drilling to my sump is the only problem.