Doctor Cannabis you out there?

there all 5 weeks into veg the ak is tiny only about 6 inches the bb are 8 and looking better but why are they so small ive topped them done a little training im using 2 ,,250 cfl for veg then will switch to 400 w hps bio bizz nutes which ive had great success with before but there just not growing please help guys im close to binning themn all