I had a ten gallon tank that i used a Coralife 28W 50/50 PC light in conjunction with an old school 15W Marine Glo flourescent lift. Just the other day i bought a fifteen that uses the same footprint and i added 2 lights ( A Current Nova t5 slimpaq 10w 10k, and a Current Nova t5 slimpaq Actinic 10W). I really like the way its looking. I was considering purchasing three more of the Acintic lamps and one more 10k while removing the 15W flourescent. So i would have 60W total of T5 while continuing to use the 28W Corallife in the front to maintain the clean look it gives. I'm just looking to see how you guys think this lighting configuration would work...