Hello there. I read your first post and afraid I don't have time to read everybodys comments, got a major paper I should be working on, so I am here to tell you about my experience with LEDs. First of all, who ever said LEDs are more expensive is thinking very short minded. Don't look at the buy-in cost to join club-LED. Look at how much you will save with electiry from extra fans, cooling, light bulbs, and the bulb electricity as well. Lets forget all the wiring for ballasts and hoods. I am incredibly happy never worrying about all the stuff I just mentioned, as I'm sure you already know of. Now for the cover space of LEDs. Before I tell you about coverage, I highly suggest you look into blackstar LEDs. They are 1$ a watt generally and work fantastic. If you got 2 500s, you would rock a massive space. Now getting to the coverage, if you put LEDs very close to the canopy (around a foot away depending on size of plant) and put all of your lights on 2 light movers, you will be golden. With two 6ft racks you can cover a 8ft x 8ft very efficiently. Light movers are key in LEDs if you are doing larger grows. When I mean large, I mean anything under 8x8ft. Anything bigger then that you should prey to god HIDs exist and stick to them until the technology gets better. I am currently using a 500w and a 240w blakcstar in my 4x4 tent and they destroy. Could not be happier. See you later cowboy.