Fluval 2-in-1 Digital Aquarium Thermometer Standard

A digital thermometer that reads both aquarium water temperature and ambient room temperature on one display, giving a more complete picture than a stick-on strip thermometer that only estimates glass surface temperature. Useful as an independent check against your heater's own reading, since a heater malfunctioning or a thermostat drifting out of calibration is far easier to catch early with a second, separate measurement.