A stick-on thermometer will solve your problem since they are outside the tank . Get the ones that can be reused; otherwise they are a pain to remove since they break when you try to.
Will the air temperature around it effect the thermometer's readings? I have a very temperamental heater that likes to occasionally blast us with a huge heat wave.
~children~
Ксениа, a beautiful yet mischievous calico cat.
Cecil & Carlos, two active and growing little froglettes