I hadn't given LEDs much thought. It looks like they are rather expensive, and there doesn't seem to be all that much information floating around about them.

I guess I'm just more confident with a tried and true method. I have seen many reports of nice yields from 250 watt lights in cabs about the size I have in mind, but very few reports about LEDs. How much LED power would I need for a footprint of about 6 square feet? How is the light penetration?

Basically, if I MIGHT be able to get away with just the 4" fan for the 250 watt HPS anyway, what's the selling point for the LEDs?