Months ago we bought a used 100 ga acrylic tank, stand, lights, sump and plumbing. My goal is to have a mixed tank being as energy efficient as possible. I'm totally open to any ideas. The system originally belonged to Mr Tubbs I'm told. Consists of a 48x20x24 acrylic tank that looks pretty scratch free now that I've put water in it. I really like these dimensions. Internal overflow on right side. Circulation is provided by 2 GenX 55 watt circulation pumps. One of which is noisey, the other one hums but doesn't turn so far. One is the sump return, the other is on a closed loop with 4 outlets about 6 inches above the bottom. There is an additional drain line to the sump from the level of the closed loop intakes. I'll take pictures soon. 2 Seio 620 powerheads also included. Lighting: 2 250 MH with magnetic ballasts and ultra cheap reflectors. 2 VHO actinics with Advance ballast that were never installed (so far I haven't found any end caps). Sump is a 29 ga acrylic that is undivided. Previously just used for a skimmer. I'm open to a larger sump or dividing this one or ? Have a sulphur denitrator to add to the sump and should probably get a phosphate reactor (right word?)? This sump probably isn't big enough for a refugium? My present skimmer is an ASM 1, I believe. Phong, is that right? Other equipment I have consists of 2 Tunze Nanostreams, 2 175 Combo fixtures with PCs, 2 seio 620s. I'm open to change almost anything. Would T5s be more efficient? 175 or 250 on a light rail? Ditch the closed loop and use Tunzes or other powerheads? Better return pump? I want this tank successful and as energy efficient as possible. Thanks for your help.