help please

hi this is my seconed grow im now growin cuttings from my first grow they have bein veggin now for 4 weeks and are still very small about a foot and half with out many leavs they are in a metere sq grow tent under a 400 watt light and are in coco i am usin canna cocco nuites i just wonderd if any one can tell me wheree im goin wrong and my fear is if i was to flower them at a foot and half i would get nothin off them ? any help would be great oh and im growin ak 47 thank you

Sounds like some good growth for 4 weeks. U can flower at any stage, the longer you hold at veg, the bigger it will get. But if u were to flower now it would probs double or tripple in size in about 6-12 weeks depending on your strain.