If you're talking about the 92 gallon corner tank, That is a perfect size to use one 400 watt Metal halide over. The color temp depends on what you want to keep. The 10,000 k's look very nice, but are not as bright as the 6,500 k lamps. You could use your fluorescent lights for actinic supplements. If you don't want to keep things that need high intensity lights, you could drop back to a 250 watt MH. I am planning on setting up a 92 gallon corner tank, and I want to use two 400 watt MH lamps, one 6500, the other 20,000 k. I want to use timers to alternate what lamps are on, with a little overlap. I am interested in keeping SPS corals, which need the higher k lighting, and clams which like the full spectrum. Those are my thoughts.
Sonny