Sorry, It was late when I posted and I didn't put in all the info. The shed will be fully insulated and built out of 2x4's. The shed is in the shade 90% of the time so I feel the temps wont be bad. There is a metal/vinyl shed there now, I put a therm in it and I've never seen it above 85*F. I was planing on spliting it 80/20 for a clone area. So what your saying is two 1000w would be better then four 600w? To me, it seems like you would have better coverage with the 4 smaller lights then two big ones, but what do I know, thats why I'm here!!! For now I'm keeping this under 1500w-2000w total. Thanks for the input!! I'll be taking pics all along this build/grow.