Im Almost positive this is a Big NO NO.

Every store site I have been to looking at their light systems all express that a HPS Ballest is for HPS and MH is for MH.

They wouldn't make conversion bulbs If they didn't need too right?

I have never tried it though lets us know if you do.

kd
kdspecial Reviewed by kdspecial on . MH bulb in an HPS? I've read that you can put a regular (non-conversion) MH bulb into an HPS ballast and have it work ok. Apparently it shortens the life of the bulb a bit, but this doesn't matter to me since I change my bulb once a year. Does anyone have direct experience with this? Or know someone who has? Rating: 5