Well, well, well. No bitching here, no questions, just wanted to say that 1 night of 12/12, and My beautiful baby grew a whopping 2 INCHES IN 1 NIGHT! I CAN'T BELIEVE IT! HOLY CRAP! I LOVE GROWING!
That's not unusual. During the first 3 weeks of 12/12 the plant usually more than doubles in height. The increase in height does not translate into more buds however. The plant grows in height but not the # of bud sites.
I totally agree with RangerDanger. That growth rate you've experienced is known as"Stretching" during Transition Phase(first 2-3wkz of 12/12 photoperiod)...