A few questions for you. First, What are you taking the temperatures with and what are the temperatures you are getting in basking spot, and cool side? What kind of bulb are you using? Is it a basking bulb. You should probably see if you can adjust the height on the 75 watt bulb. Are you using a dome and clamp type of lighting. You could also use a dimmer as long as you are not using a Mercury Vapor Bulb. Do you also have UVB lighting and what are you using for that?