I have a 29 gallon sps/ mix. The sps thrive. The lighting is a 175 14,000k watt metal halide. I feed them zooplankton once every night. And I add Randy Holmes Farley's two part additive daily. I keep mostly acropora (purple bonsai, tricolor, green slimer, blue milli etc....) They all do fine. I believe that lighting is not the most important thing with sps though. I think chemistry is #1, flow is #2, and lighting is #3. This is just what I have found to work.