thermometer question

[wickedfrags]

One is the air temperature and one is the water temperature. I believe the temp with OUT beside it is the water temperature, and IN the air temperature (but it has been a while since I owned one).

Check the instructions if you still have them (assuming they come with instructions).

Originally Posted by mytank90

i have a question about thermeters .i had a small digital one i didnt like and when and bought a larger one today .i have both in tank right now and probes in same location but they read 3 degrees different .one says tank is 77.5 other says 80.6 .which one should i belive?