They look severely stressed, to be honest. The first thing I noticed is that they look too big for the pots they are in. Are they possibly rootbound?
I'm not sure if I understand your post correctly. They started off in the sun, but are now under a growlight, on 12/12, is this correct? Answer the following questions and someone may be able to help you more:
What light are you using?
Is it COMPLETELY dark in the room in the 12 hours dark period?
Is the dark period consistent (on a timer) or manual?
What are your temps/airflow like in your room?
Do they have proper extraction, ie fresh air all the time, and old air removal?
What medium are you using?
What nutes are you using, and how often do you feed/water?
How long have you been in 12/12 for?
Sorry to bombard you with Qs, but they will help to diagnose your problem.