Good... I'm just having a tough time with temps because in my closed chamber setup... 5x2x2... a 50w basking bulb gives me the 105, and 2 others keep it high 70's on the opposite side.
Look at your tortoises behavior. They will tell you a lot be observing them. If you notice a lot of basking then temps are probably too low and vice-versa.
I've found observation to be key. My tortoises don't like too high of ambient temps as they would hide more.