I've never used MH
before, but I'm considering it for my current project. ? is, does the bulb and ballast have to be perfectly matched or can you have a more powerful ballast than bulb? I found a good deal on a 750w fixture and ballast, but that's a little more light than I really need. Not to mention I haven't found 750w aquarium grade bulbs. Can I run this ballast and a 400w bulb or will that cause problems?