I've got a couple of 600w Genesis ballasts that have a 50% power option on the dimmer switch. They are a few years old now but still great tech: low frequency square wave digital ballasts. I've looked everywhere but can't seem to find anybody using an old ballast like these to try and fire up the new 315w CMH bulbs. I've just ordered mogul socket/CMH converters and bulbs so I'm going to try this out. I was just wondering if anyone has done it before or has any advice for me. I don't see the bulbs exploding since they will be slightly under powered but not sure if they will even fire properly. Here's to hoping! I will post an update after performing my experiment. Any input on the subject would be highly appreciated.