Anyone know if you can run 28w bulbs in a 54w fixture? I have a 48" Tek T5HO 4x54 fixture that I plan to run 2 lights in (over a 40 long tank 48"x12"x16") and I want to do it low tech. The fixture has 2 switches so I can run just 2 lights, but I understand that 2x54 (108w) would probably be too much. I'm wondering if I can put 2 28w bulbs in instead.