2400 watts for an 8x8 space seems a bit overkill to me. does anyone else think that's too much? if you have any issues with heat, my suggestion is feel free to kill 1, maybe 2 of those lights. why so many 400's? like tiny tunes said, you'll get more lumen output with 2400 watts using the 600's. unless of course you got a deal on those 400 watt vertical warehouse lamps :P