Hi King,
I suggest you seriously consider up-sizing your pot; that little 1/2 gallon isn't going to do it for you. My current crop of autos (including 3 Tangerines) are all in 2 gallon. I go between 2 and 3 gal depending on the strain. The ones I have now were planted on 7/22 and they're 15" tall, have all started to flower, and have 11 to 13 bud stems each. The TDs are always like rockets for me, so I think yours is cramped. I'd also suggest you consider using a felt SmartPot and use Fox Farm Ocean Forest for your new soil.
Just some suggestions.
Take Care.