yeah bro, i got mine from wally world just like that. $10 ea. right? I just took of that plastic cover, strung 2 of them up together with some nylon and viola! I think a week should do it on 24/7. After that if you still want to give them flourescent light but not so much of it then switch to 18/6. 12 hours of light a day only is what you want when you have completed your desired height and size of you plant and you want to induce flowering. again IMO.

make sure that you hang those flouros pretty close to those plants now, after a week you'll see they have become aquainted with the world and then you can let em roll with that big dog HPS rig of yours. although for height and positioning of it I can be no use to you. lo siento amigo.

pura vida
Dion