Slow growth?

Hey everybody, I'm a first time grower, and I didn't have much money to spend on the grow so I used what I had (5 4' T12 floro fixtures) and bought 3 more. I'm growing 4 og kush clones that I got from a club. My setup is a 4'x4' panel with all the floro lights (640 watts) about 12 inches above the top of the plants. I used half 6100K bulbs and half 2700K bulbs for veg and for flower I'm using 10 2700K bulbs and 6 6100K bulbs. I put reflective insulation draping down from 3 sides of the light panel so some light is reflected back on them. They were in styofoam cups for the first 13 days, then they went into 5 gallon buckets with an organic potting soil in it. My temps are a little high but it's too hot here so it's hard to cool them, they varied between 70 and like 93 during veg, and it's gotten a little cooler now so it's varying between like 68 and 87 now. I know it's kinda hot so I have a box fan pointed directly at them about 3-4 feet away to help cool them. This has also resulted in really strong stalks, they're only like 10 inches tall and the stalks are like 1/2 inch diameter, granted this is my first grow but they seem really sturdy. I vegged them for 30 days, and they only grew about 2 inches, I'm now 22 days into flowering and they've grown maybe another 2 inches, although they're bushing out quite well. I used 24/0 for veg and 12/12 for flower. When I switched to flower I added 6 23 watt cfls to them. Is the fact that I'm using T12 lights what's making them grow so slowly? I figured the large amount of them would make up for the fact that they're not the best but I could be wrong. I water them every other or third day and they don't seem over or under watered. I had a little bit of nute burn but not more than about 1/4 inch on the end of the leaves. oh, and I nuted them with 1/2 strength ferts most waterings. I've had them for a total of 52 days and there's only like 4 inches of growth, so what do you think is wrong? I attached some pics, the first one is 4 days into veg, then the day I transitioned to flowering, then 22 days into flowering.

PS: next grow I'm having to downsize to a stealth speaker box grow and I'm using only cfl's, I know T12's were a stupid idea, it's just what I had.
Thanks,
gdoggrower

Loose that foil to start..
adding more light increases growth..

It could be many factors slowing your growth. First, it looks like you used straight soil?? Did you mix with perlite? if not, thats the problem right there. you want anything from 50-50 to 60-40 (perlite-soil). Otherwise, you have limited drainage, thus inhibiting growth, and also, the roots are getting zero oxygen, which is essential to growth. Or it looks like a possible nute deficiency. Probably N (slow growth, yellow-green top leaves, dying yellowing bottom leaves.) Why are you feeding at half strength? Maybe increase it. Also, what does the bottom of the pots look like. You need to have many drainage holes or the soil will remain wet.

Here's a link to check out to help you diagnose ur problem.

http://www.greenmanspage.com/guides/nutrientdisorders.html

I just had the same issue. First re-potted with 60-40 perlite ratio, and a week after, fed nutes. Now im having explosive growth, and a nice green color.

As for lighting, yes, the flouro's will not provide you with fast growth like you read about in peoples grow journals, but CFL's do work, but try to use 42w (highest lumen/watt ratio of cfls, and stick with the 2700k, the 5700 or 6100k are a waste of money as you get equal growth with the 2700k same as hps, and the 2700k are way cheaper). However, for the amount of money youll spend on 6-10 cfls, you can buy this 150w hps floodlight ($50 to your door).

http://www.e-conolight.com/floods/small/small-hid/e-hc1h151z.html

16,000 lumens. Way higher than anything thing you can get with the same $ in flouro's. Or, if you got the money, $120 will get you a 400w hps growlight delivered.

http://www.insidesun.com/defccf1686b8e72e72d9c136cba7cdf9.item

I used straight potting soil and it seemed pretty airy, it had a lot of large pieces of organic matter, it wasn't very fine so I thought I didn't need perlite but apparently I did. Next time I'll mix 50-50 with perlite. I drilled 8 1/2" holes in the bottom of each bucket and when I water plenty of water comes out so I don't think drainage is an issue (other than not having perlite). I was feeding at half strength because I read somewhere on the forums that marijuana is sensitive to fertilizer and half strength was as strong as you should feed it, but I could be wrong. I'll try feeding it full strength from now on. I think it's too late to repot for this grow, but next grow I'll use better soil. This is my first grow so if I don't get a huge yield I won't be dissapointed, any yield is great. I was going to use cfl's for my next grow because it's going to be in speaker boxes with only 8"x13" of area to put light and the box is only 23 inches tall, so not much room in there for an hps setup. Once I start renting a place with a garage (next school year) I'm thinking I'm gonna buy a 6' tall garage cabinet from home depot and start a legit 400 watt hps setup in that. Thanks for your help