I have a 300 gallons AquaVim reef tank, dual overflows, 3 MH bulbs @ 400watts each 20000k ,2 actinic 90 watts each, jbj 1/2 hp chiller, a reefoctopus XP 5000 skimmer (external), 2 1200g pumps as returns and a 75 gallons sump with a fuge. I also have a Redsea 250 running for about 3 yrs. The 300 gallons it's new it's been running about 1 month.