plants really slow flowering

Hey all

Would love it if somebody could throw some light on this, my plants are in week 6 of flower yet they look more like week 2.
They are blue cheese and acid. Now 30inch tall(stretch is done with), grown in coco with coco nutes, vegged under cfls and flowering under 400 watt hps. 7 single cola plants and 2 mothers, still short but bushy. coverage wise its about 1mX1m.
Temps are steady 83 lights on and 71 lights out. ph has always been 6.2.
i have given them a couple of doses of pk13/14 last week in the hope it kicks in.

There are only two things i can think of that could be slowing them this much.
1. maybe there is not enough new air going into the grow space.???
2. root bound? not sure, i know there are signs of the roots poking through the holes in the pots. but they never had any problem growing and when i put onto 12/12 they stretched as expected with hps.

i will post pics but they are very poor, just gives you an idea of how small and undeveloped the buds look with my thumb next to them.

Any advice from anybody would be great.
Thanks
Bob

Here are some crappy pics.
Also if im coming across as rude or lacking manners in my post i am sorry, i have written this post 3 times and my damn pc keeps going back a page so im trying to thin it down to just info.

Wait so are there roots poking through the holes or not? I didnt understand that part. Also what size pots are they in? How tall were they before put into 12/12? The more info the better.

Any chance you could have a light leak? take a peek when the lights are off.

I can think of two scenarios..

1.The strain. A few months ago I grew 1 platinum cheese plant under a 400 watt and let me tell you, it took FOREVER. I think I ended up flowering for something crazy like 2 1/2 months but the quality of the bud was unparalleled to anything ive ever smoked.

2. Not enough light. I had the same problem when I was using an 800 hps for 9 white widow plants.. Sure enough when I added another 400, they started booming. You could also try putting a fan inside your tent (facing the top of the plants) and set it on a timer to go off every few hours, this would make your plants move around so that they could get more light. Another thing that would benefit them is pruning. Your plants look beautiful but a little thick with leaves, if light isnt getting to the bud sites, they arent going to grow as much.

Good luck!

When looking at some of your pics I noticed some things that will definitely decrease growth rate. Discoloration in the leaves mean over fertilization. Also, Your temperature is way too high. My first grow was in a small closet with a 400w hps. It got up to 94 in that room and the plant went all the way to week 10 looking like only 4 had past. It was pure sativa, which does take anywhere from 16-20 weeks to completely thicken up. Make sure when you are watering that you allow good drainage so the salts don't build up in the bottom of the pot. fertilize every other watering. On the watering that you do not fertilize, be sure to flush the soil very good. If you cannot bring the temperature down, put extra fans in the room to cool the plant. That will allow it to grow much faster. Your bulb could also need to be replaced. Once they near their end they look bright but hardly emit any true light for plants. Hit me if you have any questions.