I thought 600W were the best?

They have more lumens per watt than the 400 or 1000.

They are more efficient! I can't believe I just saw 2 people that suggested anything different.
ShroomDr Reviewed by ShroomDr on . 600W in a C-22??? A good friend grows in the model C-22 closets (2x4 ft) using 400W MH & HPS. Realizing that more wattage equals greater yields he wants to go to 600W systems all around. But, he says that he will not be able to control the heat. I say that he will be able to do so with proper cooling and venting. What do you guys think? Can a C-22 support a 600W system? What other factors must be considered? Rating: 5