fu*k that man, you should hook that HPS up, thats a good bulb you have, and its alot more efficent than CFL or MH fot that matter (for flowering) find out the ballast it needs (i.e : S35, M59, etc.) find ot on ebay or go to a commerical electric supplier (every town has one, usually in a business area) and pick it up, id say prob 60-120 dollars... my supply shop can get me a 400w HPS bulb and ballast for 180 cash (which is alittle high but....)

thats my advice for the best grow possible

you go cheap, you grow cheap