An aquarium cooler keeps the water in your aquarium at the right temperature, even on hot days. Unlike aquarium fans, coolers work on the heat exchanger principle and are highly efficient. The set temperature is electronically monitored. All aquarium coolers use environmentally friendly refrigerant and consume little electricity. A chiller can be operated with a separate recirculation pump or integrated into the filter circuit of an external filter. Cooling units with integrated heating monitor and regulate the water temperature in the aquarium fully automatically. This eliminates the need for a separate heater.