90 Gallon

Great looking tank For SPS dominated tanks people are using as many as 1 per foot, so 4. However, for a mixed reef 2 or 3 should be okay. It seems that the people using 4, don't seem to run them close to full power anyways, it's just too much light. Really it's just whether or not you'll have dim areas, but if you have corals to put in the dimer areas, that is less of an issue. If you expand to more light loving corals, you can always add a module or two.

 

Beautiful tank it makes me even more determind to work hard on my fish only so maybe i'll one da get a reef Welcome to 3reef