I have a UVB bulb and tend to put out a 100watt basking bulb which seems fine but some people say they only use 60watts which I didnt think kept him warm enough.
It depends on the size of your enclosure and how far away the bulb is from the turtle. If you notice the turtle statying away from the heat source and never basking, then it may be too hot and you should lower the watts. If he seems fine and is basking ok then I would say you are fine.
60W spot lamp is quite enough. 100W can be too drying.
