Take it easy....There are dicks on this site that WILL say dumb shit, just because of the question he asked.
You took that post the wrong way. sorry you thought I was being rude but unfortunately this website has a rep for having trolling dicks that flame newbs.
Also it is MY OPINION that he didn't do too much research before buying that bulb. I went to wikipedia typed in HID and saw this
"Like fluorescent lamps, HID lamps require a ballast to start and maintain their arcs.
took me 10 seconds...
Great for you man for deciding to try growing. My advice to you would to do a bit more research before you buy anymore equipment or seeds. There is a lot to learn and if you cut corners something WILL go wrong.
Good luck to you man. If you have anymore questions don't hesitate to asks, I only said that because I was bummed you went out and bought a bulb without doing research only to find out you have to buy like a $100 ballast.
Maybe if he would have read a little more he would have wanted to go a cheaper CFL route who knows only he does.