I switched lights in my 15 month old sullys enclosed chamber (4.5 lbs & 8.5 in) temps now read all over in the high 80's but mostly in the mid 90's. Is this too hot? Basking is 109..... the "cool side " is 86 to 89.
Sounds a bit warm to me. I'd take another look at toms how to thread and double check. My guy is huge and lives outside so I'm not much help with little sullies.
Hot spot around 100ish. Cool side 80ish warm side 90ish. That's what works great for my sulcatas.
Your torts actually should be able to tell you. Take a close observation. Study him. Ex. If he is always under the heat lamp, he's trying to stay warm. If he's always over in the cool side then it may be too hot etc...