I think the videos will speak for themselves
Part 1
http://www.youtube.com/watch?v=BNf-P_5u_Hw
Part 2
http://www.youtube.com/watch?v=qc-mrJf45Hg
Part 3
http://www.youtube.com/watch?v=IjAegPhQOUg&feature=related
Where we are
http://www.youtube.com/watch?v=4O67AZfUMXw
Try this it worked for me, if you dont have it like this already. Make sure your fan is SUCKING the air past your light not blowing it, I have my 6''400 cfm attatched DIRRECTLY to my 1000w hps and doing that by itself lowered my room 10 degrees F. ex. AIRFLOW-----> ducting -->...
^^^ ya kid your way off, adding more plants to the same lights wont make the other plants smallerm because the light you put the excess plants under is not being ised anyway, now if you move the light farther away to compensate for more plants then it will affect yeild.
So let me get this...