Due to my tank having an internal c2c overflow, the 6 bulb ati sunpower would be a tight fit. The bulbs are stretch almost exactly from the overflow to the edge of the tank with an inch and a half to spare, if the fixture was resting on the tank. Would I be better served getting a 4 bulb fixture? I am asking in the SPS forum as my goal is to keep a variety of Montipora.