Help with my plant problem please

They have been in veg for over three months.cant figure what the problem is.usually i do pretty good. But they need more help than i have the knowledge of. The run down. Was under t-8 floros for months.move to a 400 watt mh. Temps between 70-80. Fox farms of. Batanicare nutes. The full shebang, i did battle spider mites for a while but i believe i won the battle and war. They clones were given to me with the mites. Kinda a thanks for nothing thing. Oh well. Moving on. Got two good fans for vent.. Here are some pics. Hope it helps you to help me.

root bound maybe? that looks like a pretty small pot for being 3 months plus. that can lead to a host of other problems.

...how long have they been showing problems?

Hhmmcould be. I believe a 2 ltre aeropot

..how long have they been showing problems.
FOR A WHILE WAS LAID OFF TWO WEEK AGO. SO BEEN PAYING A LOT OF ATTENTION LATLY. BUR BEFORE THAT THEY WERE NEGLETED. PROB. HAD PH PROBLEMS CAUSING NUTE LOCK. AND OTHER THINGS IM SURE

Looks like a P defeciency probably due to Ph problems, do you have any lime. Make sure you measure the runoff.