Okay, just use the 2 bulbs for now until you get CO2. Trust me on that one! I'm sure other people will chime in and agree. I came from reef tanks, too, so I understand what you mean when you say it seems dimly lit. But dude, 108w of high output T5 lighting is already putting you up in the lowish-medium light category. 216w is just waaaay too much for a non-CO2 tank.
It's perfect for a CO2 injected tank, though!
