a 250hps sounds mighty fine for finishing 1 plant, but how's the ventilation and temps? I'm using MG organic garden soil and the MG ferts. But I dilute to 1/4 str while they are babies. Also a little 20$ ph kit will help. Gona shoot ya a couple links. Covers basic neuts, temps, lighting, ventilation. Ya know. The best way to look at it is to put yourself in the plant's place and see if it's too hot, too moist, and so on.

http://boards.cannabis.com/basic-gro...-dankness.html
http://boards.cannabis.com/indoor-gr...-progress.html

Use those two threads in unison. You'll learn quite a bit.

beSafe:jointsmile: