DIY metal halide question

[Coffeeman]

I believe that bulbs 10k and over use a pulse starting ballast which is a different type of ballast.Not too sure though,I bought one of these ballasts once from albright lighting, it was 175 watt and I got it to fire a 14k bulb.I found that the ballast was very loud even in a ballast box,not to metion the heat.If I was you I would email Sun Aquatics,they were offering a 250 watt electronic ballast for only $119.00.