ballast question

[reefhawk]

ok there is no such thing as a stupid question ......right? Are all ballasts compatable with metal halide lighting? I was at a hydroponic store where i bought my mag 1200 for a reasonable price and the store owner told me that his 400 watt ballast he had on sale would be perfect for my german metal halide bulb (also 400 watt). So I took him at his word and took it home fired it up and it seemed really hot. Turned it off after an hour worried it might raise tank temp. Next morning plug it in.... no light. Look at the bulb and one of the metal components inside is unwelded or otherwise not connected. Took the ballast back, they tested it said everything was ok and there was no contenuity in the bulb. Tried to sell me a full spectrum bulb for $69.00 and told me they are great for reef aquaruiums. I knew then this guy had no idea. Told him - no, that was wrong and would cause no end of problem in my tank. He asked me if I was sure and was quite surprised I wouldn't use his bulb. Told me any 400 watt ballast is compatable with any 400 watt bulb. Is he right? Doesn't want to refund my $ on the ballast and my $160.00 bulb is toast , mind you I got 6 months use out of it with the original ballast it came with. Ok now I have to explain I set up a second tank and put a new bluer bulb in the original ballast which is why I bought the second ballast. Confused? I am. Or am I?