Most likly the ballast would be fine and the bulb would burn out. The HPS needs an ignitor to run but as I understand it is basically the same besides that. If you have a MH ballast it is good for only the MH. If you got a HPS ballast you can bipass the ignitor and run a MH. Some people say they can run a MH bulb on a HPS ballast with out bipassing the ignitor but I do not know the long term effects.
Sparrow Reviewed by Sparrow on . Mh and HPS running on same ballast hey guys, i was just wondering. I bought to ballasts and i got a hps light and a mh and im running my mh now, but i was wondering, im not to sure if it matters which light goes into which ballast i bought which looked like 2 ballasts that are the same but i got 2 different lights, would that blow my ballast if i put the wrong bulb in casue from what ive read im underthe impression that it makes a difference but when i bought them i wasnt told anything about that i was just given 2 ballasts with Rating: 5