Height problems

Hi,
I have an indoor grow with around 8 plants,
6 of them are growing lovely in have been on 12/12 for the past week, the other 2 have not grown much at all, halfway through veg they stopped growing and the only changes i've seen is a few small leaves appearing very slowly though unlike the other plants growing a good few cm a week, i have the plants under a few 300w cfl's.

any help would be very much appreiated! thanks.

Genetics, environment and lighting are many factors to consider. Pictures help. More info please.

hmm i think its mostly genetics but environment also i have 5 plants and one of them was just a runt from the start even under identical conditions, it is currently flowering but much less vigorously than the other 4.

I will take some pic's as soon as i have found my USB cable and upload them, i don't know i its worth keeping them or getting rid, some of the larger ones lower leaeves has started touching one of the small plants so im a little worried.

lol so what if they touch? what exactly are you worried is going to happen?

if they touch the roots of the larger plant maybe taking all the space from the smaller one's.
it's my first proper grow, grew 1 female NYC diesel around 4 month's but the set-up was 1 cfl and a cupboard, i have gone all in and invested a little in lighting and cooling as i know what i put in i will get back.

cheers.

and finally one of the smaller plants: