I currently use a 48" T5 as the light source in my tank. I'm hoping that someone out there can provide me with the specs of the right/best bulb to use for the T5 as well as some of the hardier corals/macro/photosynthetic creatures they would sustain. The tank is on the deeper side approx. 30" deep. I don't want to shock the fish that are in there now by increasing the light dramatically ie: converting to metal halide with out some transition. Any suggestions if T5 isn't ample what metal halide system should I go with. I have been looking and I found one on ebay for $300, I'm wondering if the fixture would be just as good if replaced with quality bulbs as a $700 fixture, they look the same to me.