Hi all, in my setup I hesitate to even tape the probe to the carboy. This is because the temp of the beer is going to lag behind the air temp in the freezer. So if you want to hit 70F in the carboy for a German Hef, if you have the probe attached to the carboy, the air temp in the freezer could drop as low as 65F or lower before the carboy cools down. Then, the air will still be cold and the carboy will continue to cool beyond where you want it. The best approach is to try to control air temp inside the freezer and either use a thermal well or a temp tape (fish tank thermometer) to find out what the differential is between your beer in the carboy and the air temp. Then adjust the set point accordingly. This will keep your beer from over heating or over cooling after freezer goes off. For this method, probe placement is important. If you have it too high in the air over the floor of the freezer, the freezer will be too cold. The set point will turn off the freezer and the walls will remain very cold and continue cooling the air, which will then continue cooling your beer. But, if you put the probe too close to the floor of the freezer, then the controller will turn the freezer off before the air has a chance to cool down. I set my probe about 2 inches from the floor. If I have my set point at 68, my beer is about 70ish. Also, the air at the top of the freezer is 70 and the air at the bottom of the freezer is 66, leaving the air in the middle the perfect 68. In live in SoCal where right now we're having over 100 temps, the freezer only cycles a couple times an hour.