[GIF] Leaves curl under, lower leaves yellowing

Hi guys, haven't posted in a long time. Can someone tell me what might be going on with this plant? Each frame in the GIF is 12 minutes, so the loop is 2.4 hours real time. Consider that it may not be enough time to indicate an actual problem, but the leaf on the left of the center bud that curls under looks suspicious.

1) http://imgur.com/qYR8x
2) Indoor soil grow
3) Watering when soil is dry
4) Flowering stage

The bottom of the planter had a bit of water collected in the bottom, and the soil was damp. Not sure if maybe it's over-watered or if there's a nute problem. Perhaps P deficiency? Buds are kind of small. I will collect more video frames as time goes on, but I started to notice this, and I'm a bit concerned.

N deficiency is kinda common on flowering becuase bloom nutes dont have N, or atleast not much of it. thats also shown by yellowing of nutes from bottom up

not sure wtf that thing is you posted, that .gif image. hard to tell whats going on if you got purple lights on. hell add a disco ball too man.
check pH. that could be the cause of your issues.

i have seen leaves curl under most of all when pot is small and root is bound. can't tell for sure though.