bearded dragon growth

Question
I have 3 dragons 2 of them are growing good but one has not growen very much at all since I got them, what can I do?

Answer
 If they are sharing one enclosure, the small dragon is being intimidated by the others from his fair share of food and basking area, so it's time to separate the three.  If they are in separate enclosures, it could be a genetic thing.  Not all beardies grow the samw size, even from the same parents.  Many of my second generation beardies varied widely in size, from big 20-22" down to little 15" feisty mini beardies.  Just as adorable, just as healthy.  Personally, I would not breed the minis since I am breeding for size and hardiness.