newbie 1st time grow

this is my first grow i have them under 600 hps lights and theyre under 16/8 they r 2 weeks old and i got them as clones from the cannibas club..out of 7 plants 4 are growing very nice but 3 of them seem not to be growinng..and i have then in those cloths smart pots and the roots ae coming out thru the cloth is that normal?

get them in some nice big pots

Is that foil? If so take it down and replace it with white paper... thats better for the plants. With foil you gotta worry about heat spots....

and as for the roots... you should transplant them into bigger pots.