I have a 9002 in my 28 Nano with a 7 gallon sump/fuge. It works fine. I used to run a Aqua C Remora pro, which did a slightly better job of skimming, but made way to much noise. If cost is no issue, the Tunze 9005 would be a great choice, but even used they are costly. Tunze is one of the few companies who put realistic tank size ratings on their skimmers, you do not need to use a skimmer rated at double what they claim unlike most other makers. I have a mix of SPS, LPS and soft corals in my tank, the 9002 keeps my water very clean (well, the refugium helps also).