im also a beginner but your better off useing somethin other than miracle grow if you can(something with no chemicals) but miracle grow would b ok if u have to use it,most the people here will tell you that youll get fuck all buds with that light,you might get a little bit but only for a couple of spliffs,

if you wana keep it simple then just get one 150w fluro,put 3 plants under it and keeps cit only 2 inches away from the tops of your plants,other people will tell you that u need more lighting than that but at least youll get more buds that way,beter then the light you have now and youll get a fluro for less than a tener