Good job dude! Looks like one is starting to do better. I'm not sure if anyone mentioned this but all of those plants need to be in their own pots! Otherwise they will fight for the root space, and only one will win... that's why that smaller plant is not doing so hot.

Why did you switch to 12/12? You said you are going back to 18/6 for a while, and this is the best thing for you to do at this point. Those plants should bulk up a bit. when you begin to flower, be wary of the bud weight. It looks like they'll break if you're not careful.

Good luck!