Fish cannot produce body heat on their own, so they depend on the temperature of their water to stop them from getting too warm or cold.
An aquarium heater helps regulate the temperature of the water throughout the day and night. Tropical fish require a heater as they originate from warmer climates. For most tropical fish, a water temperature of around 78°F is usually sufficient.
Some species prefer slightly hotter or colder temperatures, so always double-check the specific care needs of your aquarium’s inhabitants.
What’s Your Tank Size?
The size of your tank is vital for choosing an appropriate heater for your tank. As a rough estimate, you use between 2.5 and 5 watts per gallon of water. For a 55-gallon tank, I’d recommend using between a 150-watt and 300-watt heater.
However, this also depends on the type of fish you own and how much the temperature of your water needs to be.
What Fish Are You Keeping?
The type of inhabitants in your tank is important for working out which wattage heater you should use. If you own fish that live in very warm waters, then a high-watt heater might be a good idea for ensuring the water is heated properly.
In contrast, if you own cold water fish, then a heater might not be necessary as long as the room their tank is in remains at a consistent temperature.
