This Swell Solar Digital Thermometer is a great way to monitor the temperature inside your aquarium, without the need of batteries or an external power supply. All it needs is the power of the sun, and even then it doesn’t need a lot!

Thanks to its sticky back, this Swell Solar Digital Thermometer can be quickly and easily attached to an outside surface of your aquarium. Make sure the metal measuring probe in the back of the thermometer is touching your aquarium’s glass.

Once set up, you can start monitoring your aquarium’s temperature. This Swell Solar Digital Thermometer can measure temperatures between 0-70C (32-158F) at a precision of +/- 0.5. You wont need that full range for your aquarium, which is most likely to fall between 20-34C (64-93F). You can also toggle between Celsius and Fahrenheit by using the button on the side of the thermometer.