Quote Originally Posted by ultimatefreak48
Ok... Im looking into getting an HPS light, 150 watts possibly, but do I absolutely need a ballast... Ive been looking around to see if i can find out if i do or not and I cannot find a clear answer. Can I just plug it into a regular lighting fixture?
Yeah, you need a ballast. HID lights ("HID" stands for "High Intensity Discharge"...both MH and HPS are HID lights) have to have a very regular energy current flowing into them. The current that flows through a typical outlet fluctuates too much, and that fluctuation will cause the lights to fail.

I know people that really like to DIY everything built their own ballasts, but I think it's kind of kooky for 150w and 250w lights. You can get a full 150w light system with a bulb for about $80-90 shipped...that's not much more than cost of the parts and bulb. A 250w switchable ballast is $150.

If you're thinking of getting a 150w HPS, keep in mind that a dual clamp light CFL setup with 180-190w will set you back less money, is more flexible (you can get daylight CFLs for vegging), has less problems with heat and therefore ventilation, and will put out nearly the same amount of lumens.