Hi folks. I have a pretty sweet custom dual-600W ballast that I bought a month or so back off my local ebay service. The problem is, the bulbs I'm looking at buying are 400W (600 aren't available, period.) I've read a lot of conflicting info online regarding mismatched bulbs and ballasts, and for the life of me I can't find a good explanation on how they work (either too simple/no real info, or way over my head.) Is there an electrician on the boards who can give a straight answer on using a set-up like this? Not just if it should be done or avoided, but why? Or just someone to point me to a good source so I can look it up my self would be greatly appreciated. Thanks!