Holy slow response... sorry laversace. The answer is YES! I've been running just the LEDs (w/o optics) for several months and everything is doing great.
Here's a recent shot of the tank with only 30 3watt LEDs...
My plan is to pick up optics in the next month or two.
Tom
You only have 30 LEDs over your 75g? Dang, I'm running 52 over my 75g. I have to get over sometime to see your setup, it looks great.