I have a Coralife Digital Thermometer that today is giving me abnormally high readings. Normally the tank runs about 78 degrees. Today it is saying 85.6. The water definately does not feel that hot. In fact, the water feels perfectly normal. Everything seems happy in the tank too. To check it, I pulled the probe out of the water and let it sit in the air for a while. It quickly dove to the same temp as my houses thermostat, which is 74 right now. I'm confused. Do ya'll think my thermometer's gone bad, or has my heater failed on? What would you do to figure out the problem?