HPS bulb works in modern electronic ballast, but not MH bulb. Any reason why?

[Landracey]

Last year I finished flowering my girls with a Lumii Black 600w electronic ballast, using an HPS bulb.

This year I am trying to veg with MH bulb, using the same ballast and reflector kit. I thought that modern electronic ballasts are double use (HPS and MH bulbs), and that is advertised to be the case with the Lumii model. Maybe I'm wrong about that?

Also would the reflector might be the issue?

I don't really want to approach a shopkeeper about it and end up buying a separate ballast and reflector kit, so I thought I'd come here first and ask advice. Thank you.

 

[bluter]

Last year I finished flowering my girls with a Lumii Black 600w electronic ballast, using an HPS bulb.

This year I am trying to veg with MH bulb, using the same ballast and reflector kit. I thought that modern electronic ballasts are double use (HPS and MH bulbs), and that is advertised to be the case with the Lumii model. Maybe I'm wrong about that?

Also would the reflector might be the issue?

I don't really want to approach a shopkeeper about it and end up buying a separate ballast and reflector kit, so I thought I'd come here first and ask advice. Thank you.

they'll have a switch on them for the different bulbs. older type require re-wiring internal. also need the right bulbs for each.