ballast question

i am looking to upgrade my indoor veg chamber from 175mh to 400mh now i already have a 400w fixture and hood but the ballast code is h-33 which i believe is mercury vapor. i was just on ebay and pricing ballasts and saw a "metal halide" ballast that said it would work with a m-59 lamp(400wmh) or a h-33 lamp (400w mercuryvapor) my question is are mercuryvapor and metal halide ballasts the same ive noticed both lamps have similarities (i.e.both use arc tubes that are charged differenty)if anyone could help me out it would save me calling an electrician and sounding like a dumbass thanks!!

ok ill answer my own question, mercury vapor lamps will work in metalhalide ballasts but metalhalide lamps will not work in mercury vapor ballasts i found this out after about 4 hrs of research

you can wire a mercury vapor ballast to fire a MH bulb. I will see if I can find the DIY that ive seen showing how to do. but to answer you question i am pretty sure if you match the ballast codes you should be ok. but like i said im am gonna try to find that DIY.

i don't know if I am reading this right or not, why not get a conversion bulb?

conversion bulbs suck you loose hella lumens and a shitload of kelvins.

hey seedless i think what has to be done to rewire is a capacitor bypass but if you can find that info would be great thanx!