It is vitally important that you observe and control for any temperature fluctuations in your aquarium, as these could lead to health issues in your fish such as White Spot, amongst many others.
Adhesive thermometer for use externally on the aquarium glass/acrylic. Measures aquarium water temperature via heat transference through glass/acrylic.
Displays temperature reading with the use of thermochromic paint. The measured temperature in both Farenheit and Celsius lights up along the strip.