I don't get this t5 thing. Just do it right. Take away the heat, EVERYONE knows that metal halide lighting is the most efficient, complete lighting source for reefing. I have watched so many corals die from people not using enough light. Then you limit yourself from tank upgrades. I run t5's, vho and pc's for transition only. I could care less about what they do for my coral because metal halide does EVERYTHING for growth of ANYTHING in my tanks. I use actinics just before (not during) and after the MH cycle and this is only for transition. My tank is 22 inches deep. I am not looking to upgrade to a custom tank thats 30 inches deep. I will not have to add or upgrade lighting. My MH will do just fine. Sure, I got a chiller but it barely ever comes on. I just planned for MH and installed ice cap variable fans in the canopy and that keeps my temps perfect. Plus the fans aid tremendously in evaporation. Perfect setup. I'm just not feeling the whole t5 hype. Plus NOTHING compares to the look and effect you will get from MH. Just my 2 cents.