HEY~ i have a question. how about i get the 1000w dimmables, get 1000w bulbs. run everything at 600w, and if it does not produce like i think it should or could, i can then just switch it up to 1000w and be where i want to be. im not disagreeing with you by any means. i have been told a few times that 1000w is a little much for a 4x4. but a lot of grow books, and other growers DO advise using or say you can use a 1000w in a 4x4. i know a 1000w would be more efficient in a 6x6 tent or space. im mostly thinking about the future. 1 day, these tents will be gone, i will be in my own house, and then i will use 4 1000w in a 12x12 room. that is my ultimate goal!!! i also go by watts. i have heard 1g/watt is about average. in my head 600w is less then 1000w. my 1st set up involved a 1000w light and a light mover. how does that sound? i just hear my buddies grower getting 2.5 pounds from 2x1000w lights. in a 4x8 tent. is it safe to say that i could get 5 pounds out of a 4x8 with 2x600w lights? i have a pretty good feeling you will say "yes"!