Healthy fish and plants. Fish depend on the right ambient temperature because, being cold-blooded animals, they are not able to adjust their own body temperatures. The vital functions of cold-blooded animals decrease with falling temperatures. The right aquarium temperature is therefore very important to ensure the animals maintain their food intake and guarantee a smooth continuation of all metabolic processes. Depending on the origin of the fish, the temperature they feel comfortable at, varies. With the JBL aquarium thermometer Premium you can monitor the temperature to an accuracy of 0.5 °C. Thanks to a suction cup the glass thermometer can be easily attached inside the