Can I use a MH bulb

I scored five lights from a buddy that was tearing down a building. The bulbs are no good. They say mercury vapor - 400 watts. I took one to a commercial lighting store, and the guy told me it was a Metal Halide. I know that's not right, it says Mercury Vapor right on it. Can I use the MH instead of the MV? The fixture doesn't specify MV.

Oops!
The bulb is a Multi Vapor MVR400/U from GE. Still, could i use a MH in place of it?

Most metal halide bulbs are classified as multi vapor because other gases added to the bulb to increase performance and lifespan. The bulb that came out of the lamp is a 400w MH/MV universal position bulb. I'd stick with that same bulb for vegging... gives out a decent amount of blue light, then switch to a HPS for flowering for more red spectrum. But if you're on a budget you can use the metal halide the whole way through, you just won't get the yield a HPS can deliver.

Thanks, man! I thought about using a conversion bulb I found for 90 bucks on line. It's supposed to be a HPS that can be used in the MH ballast. Anyway, thanks again, I didn't want to go blow 35 bucks just to watch it burn out when I started it up the first time.

Thanks, man! I thought about using a conversion bulb I found for 90 bucks on line. It's supposed to be a HPS that can be used in the MH ballast. Anyway, thanks again, I didn't want to go blow 35 bucks just to watch it burn out when I started it up the first time.