Contrary to popular belief T5's burn hot as well, its just the energy is spread out over a larger area. With the correct use of fans you could do away with the chiller. Is your house air conditioned? This will help keep the atmosphere around the tank constant with fans blowing the hot air out. Check out Reef Geek for good deals on retrofit T5's kits, Tom at Socal has great deals (possibly better) on T5's. They are 48" long bulbs, 54w each x 10. 5 ballasts with 10 reflectors.