First Auto Grow

This is my first auto grow, and this auto has been very interesting. She has been out of control with growth. I have had to top, and defoliate which I've been told not to do with autos. Pretty much its whole veg cycle it had slightly burnt tips. So I've been feeding it very little thinking it was nute burn(I'm no expert). I also backed the lights off a little. Its about 2 weeks into flower and is yellowing a little, so i flushed and fed.