not to be a smart ass (well kinda am but not really), how about trying to minimize stresses for the plant to increase THC content?!?... if you do everything right for the plant; and maybe give it all organics with a good and strong light... you might get the max out of your plants... but to just do one little thing to increase THC/yield/anything... is just too, imaginary maybe, just do your best, grow the plant (with many clones) for a few years to get to know the strain/phenos, and im sure you will get "more" thc per-say
"Peace out, Azhden"
"Are you sure you not American? Cause you're being kinda a dick about this." LOL!! funiest thing ive heard in a while.
"To make marijuana against the law is like saying that god made a mistake."- Bill Hicks
"To all those lost, but not forgotten, RIP"