Lighting Question

[dsaundry]

Ok, here is what I am thinking of doing in near future. I currently have a 72g bowfront that is set up as my reef tank. It is currently set up with a fluval fx5 and a wet/dry filter set up under tank. It also has an aquaclear 500[110] as my Rowaphos holder and a few powerheads as well. It has about 80-90lbs of rock and several soft corals and fish are as follows. Pair of percs, foxface, sailfin,bicolour blenny, pseudochromis,[2] scooter blennies, a coral banded shrimp, 2 manderin dragonettes, and several snails+hermit crabs+ a sea hare. Tank has been running for about 6 months now,I cycled it for 2 months prior. For lighting I have a 48" 2x250w metal halide with 4x65 actinic pc's. I do regular water changes and dose as well. Tank seems to be doing very well. I am currently setting up a 90g predator tank. The only issue I am currently having is that I find the halides can heat up the 72 bowfront by a few degrees and even with cutting the time the halides are on, it still seems to get too warm. From 28.7 degrees it has jumped to almost 32. So here is my question. If I take the halides off the 72g and use them on the 90g and purchase a t5 6or 8 light fixture for the 72g would I see a big difference in heat and would this be a peferred method of lighting the 72g? Suggestions anybody??

[kwirky]

try mounting a fan. fans do well to dissipate heat from lights. It'll increase your evaporation a little so you'll have to keep on top of that too afterwards.