For essentially covering a 15x15x15 area, I would say a 250 is overkill. Not to the point of damaging corals, but most definitely to the point of wasting electricity and $$
well i upped the depth to 18 inches. I just want to make sure I have plenty of light. And the price difference is like 20 bucks between a 150 and 250 aquamedic.
Oh thats not too bad... Operating cost, including electricity and bulbs for a single 150MH is about $100 per year and $140 for a 250MH. I thought the initial ballast setup was going to be more exensive.... guess I was wrong . If its gonna be 18" deep then thats probably a good idea