I have the light 30cm from the tops of the plants, i wouldn't put them any closer than that with my 400w MH, and i just transplanted to 25cm pots.
They were a bit stunted in the beginning. I wasn't fertilizing them properly,which will account for there smaller size.
I'm using a soilless mix with zero nutrients, which you have to fertilize a bit earlier i think,cause they only really started growing after there first feed, but they doing great now. :jointsmile: