What is the ambient air temp?

I think I would reduce the power to the light (or increase the distance) The light will have the most effect on the over all temp UTH basically only heat what is directly above them. You are using a thermostat with the UTH? I hope so. They are not an optional item. The keep the temp of the UTH from going to high if the room temps change. Even with low wattage elements this is critical.