I have a johnsons controls thermostat hooked up to both my snake tubs. I have it set for 93*. I have the probe taped to the flexwatt outside the tub. I have been measuring temps all day and I keep getting crazy readings. I have used my thermometer with a probe inside the tub and it reads 85*. I use my temp gun (I am thinking its not very reliable :/) and it says 100* and the thermostat says 93*.

WHAT IS RIGHT??