400 watt HPS/MH (Grape God Bag Seed)

Well it has been at lest 3 weeks from seed now!!, it is still pretty small well it is about 5 inches tall but pretty bushy, nodes are close together.
I have been using a 400 watt M/H and with a 18/6 light cycle. just introduced it to nutes im using a light dose of GH flouro duo A&B.

If anyone takes a look at my journal and can see if anything is wrong please let me know, i also keep my light about 3-4 inches away from the top. Im not sure how far away the light should be but it has not burned my plant yet so i think its fine, but if not someone please let me know!!

another thing is how long should i veg for ??? i dont want it to bget to big cause space is a little bit of an issue !! but i would like to get at lest one and a half oz's from it!! I just hope that she is a female so it doesn't feel like such a waste of time.

anyway here are some more pic's, IMO she is looking good !!!