If you think critically about it all three temp readings your getting are correct. The probe is directly on the tub with substrate insulating it, so it should read higher then anything else. The temp gun is just measuring the substrate temperature with nothing to insulate it. And the unit is measuring the ambient air temp above the tape.

It seems like your pretty much dead on where you want to be. None of those readings are remotely close to being capable of burning an animal

Sent from my SM-G730V using Tapatalk 2