FWIW, if you are keeping only SPS and clams, go the 250w mh and 2 T5's. If however, you are like me, and you s.o. decides they want a LPS and are in love with it, you will want the lower light areas for that. I have a 150w MH and 2x65 cf and my sps frags still grow well on the sand. Depends on what you plan to have. Yes, you can put SPS anywhere with the 250w, but that limits other corals you may want (some chalice's like lower light too). HTH,