Aquarium heaters with thermostat

Thermostat

— the ability to set the desired water temperature and maintain it automatically: the heater turns on when the water cools down and turns off when it reaches the set value. This mode is important as it prevents "overheating" and constant monitoring, providing fish and plants with stable conditions without sudden changes. Compared to simple models without adjustment, the version with a thermostat is safer and more economical: it doesn't heat continuously and is better suited for sensitive species, although accuracy may vary among different models, and it's sometimes useful to check readings with a separate thermometer. Usage examples: set it to 25–26 °C for a tropical aquarium and forget about manual switching, or slightly raise the temperature during fish treatment and then revert to the previous value with a single turn of the regulator.