Put it under the big light. The hps will kick it into high gear. Make sure the light isnt too close. Also, use a small oscillating fan to strengthen the stem. Good luck!!
Yep sounds good, watch her close at first - if she shows any signs of heat stress (might wanna google this if you aren't sure) then move it up further. If she looks good you can also try slowly lowering it, but no closer than 12".