I am not sure if the fixture would be able to handle the heat of the 250W. If there is a similar Sunpod out there with a 250W, you can probably do it. Is it financially feasable or would it be cheaper to buy a new light kit? My 250W MH cost $65 for the bulb, $10 for the fitting, $99 for the ballast and $15 for the aluminum canopy.