MH bulb in HPS ballast

[jiggerman78]

Anything wrong with it? From what i've read MH run's at a higher internal pressure than a HPS. I can understand how putting a HPS bulb in an MH ballast can be dangerous, but how can MH in an HPS ballast? They both retain the same inner shape as far as the internal structure goes. I'm fiendin to put this MH bulb in my HPS setup anybody have any suggestions/ personal expereince/ bad calls.

[Anony]

I cant give you a specific answer why, and I think you know its proly not a good idea.
Plus conversion bulbs are o.k. from what I understand. Im curious to know what happened when someone tried this, cause you know someone has....

[ISTANDALONE]

nothing might happen, something might happen. best case scenario the light lights up a little or a lot. worst case scenario the bulb blows up, getting glass and whatever nasty elements/chemicals/toxins are in the bulb all over the place. just shell out the dough and buy a conversion bulb. do you really want to go to the ER and explain how you got a shard of glass from an hid bulb in your eye?

[toastybiz]

Do not do it. Use a MH conversion bulb. HPS requires an igniter that is built into the ballast and MH does not. So unless you use a conversion bulb the igniter will try to ignite a MH bulb not equipped to handle it.