I have an older model aqua medic 6' aqua space light that I no longer need. It's free to whomever wants it. It has 3 250w hqi's in it, one of them doesn't work and not sure if the pc's work. I spoke with one of the guys from aqua medic who said they can replace the three ballasts outside of the fixture for about a hundred dollars each or so. Or you could just replace the one ballast.
Jerry
Jerry