i asked the same thing too, yes you need to have a ballast. either built in or seperate.
twoguysupnorth Reviewed by twoguysupnorth on . HPS in a regular lamp? Does a hps bulb require a special fixture i know ive read alot about these ballast for the real high wattages but for a 50 watt or so hps bulb does it need any kind of special fixture or can any fixture that can handle that wattage support a HPS bulb, Thanks in advance. Rating: 5