I know a generic reference of 10X tank size should be turnover rate. However, for a reef it needs to be more like 20X-30X, some even say 40X!!! I'm shooting for the 30 range in my tank. Flow and water turbulance are a good think in a SW tank. Also think about pointing a powerhead so that it ripples the surface water. Hope I helped!! _________ 55 gallon slowly growing reef aquarium, 85 lbs. live rock, 2 1/2" sandbed, 1 False Percula Clown, 1 Sixline Wrasse, Tetratec PF500 filter, 2 110 watt URI Super Actinic VHO actinics, 2 250 watt metal halides with Reef Optix 2 reflectors powered by Blue Wave 3 ballast, born 1/3/08 My Tank Thread My Tank Video  |