adding an extra light 4 weeks into flowering??

Say I have 1 600watt light over 10 plants there half way through would adding another 600watt light make the yeild alot better for the final 4 weeks??

i would. twice as much light should mean bigger plants

what he said.

If you would have had 1, I dont think it would make too much difference, but with 10, some plants dont get as much light as others. Get more lights!

(coming from the nub who is using 4 x 14w CFLs )

yeah i wasnt sure with the buds being pretty big already half grown wasnt sure if it would help ill give it a try when i solve my heat problem

heat problem?

If that's the case it may be more effort than it is worth trying to move another light in.