Ballast Question

[Cbravo212]

I have a 36" 175W HQI Metal Halide with 2 65W PC bulbs, and 4 LEDs. It is almost impossible to find a double ended 175w bulb other than on Ebay, and I am not sure if the quality on those is even worth the 25 dollars.

Can I use a 150w bulb in its place or does the ballast only work for a 175w bulb?

Thanks.