Aquarium heating is a crucial aspect of fish keeping, as the temperature of the water in the tank can
significantly impact the health and well-being of the fish and other aquatic life living inside. To maintain
a consistent and suitable temperature range in the aquarium, it is important to invest in an aquarium
There are many different types of aquarium heaters on the market, and choosing the right one for your
tank can be overwhelming. This blog post will explore the different kinds of aquarium heaters, how they
work, and how to properly use and maintain them.
Types of Aquarium Heaters
As we said, Heaters must be placed according to the tank’s volume. There are three main types of
aquarium heaters: submersible heaters, hanging heaters, and external heaters.
Submersible heaters are the most common type of heater used in aquariums. They are placed inside the
tank and easily hidden behind plants or decorations. These heaters are designed to be fully submerged
in the water and use a thermostat to regulate the water’s temperature. Submersible heaters come in
various sizes, so it is vital to choose one that is appropriate for the size of your tank.
Hanging heaters are another option for aquariums. These heaters are mounted on the back of the tank
and are suspended above the water. They use a heater element to warm the water, and they also have a
thermostat to regulate the temperature. Hanging heaters are a good choice for tanks with limited space
inside, as they do not take up any space in the tank itself.
External heaters are used in larger aquariums and placed outside the tank. They use a heat exchanger to
transfer heat to the water and are often used in conjunction with a chiller to regulate the temperature.
External heaters are more expensive than other heaters but are also more efficient and can heat a larger
volume of water.
How Aquarium Heaters Work
Aquarium heaters use a heating element, such as a coil or a ceramic rod, to transfer heat to the water.
The heating element is surrounded by a thermostat, which monitors the water’s temperature and
adjusts the heater’s heat output accordingly.
Most aquarium heaters have a dial or a digital display that allows you to set the desired temperature for
the water in your tank. The thermostat will then work to maintain that temperature by turning the
heater on and off as needed.
It is important to note that aquarium heaters should not be used to increase the water temperature in
your tank rapidly. This can stress out your fish and cause them to become sick. Instead, gradually
increase the temperature of the water over a few days to allow your fish to acclimate to the change.
How to choose the right size of the aquarium heater
To choose the right aquarium heater, you should consider the size of your tank and the desired water
temperature. Here are some general guidelines to follow:
- Determine the size of your tank: The size of the heater you need will depend on the size of your
tank. Generally, it would help if you aimed for a heater that can heat your tank by about 2-5
degrees Fahrenheit per hour.
- Consider the desired water temperature: Different fish and plants have different temperature
requirements. You should research the temperature needs of the species in your tank and
choose a heater that can maintain the desired temperature range.
- Consider the ambient temperature: If you live in a colder climate or keep your tank in a cold
room, you may need a larger heater to compensate for the lower ambient temperature.
- Consider the wattage: The heater’s wattage should be sufficient to heat the volume of water in
your tank. Generally, you should aim for a heater with a wattage of between 2.5 and 5 watts per
gallon of water.
- Use a heater with an adjustable thermostat: It is essential to use a heater with an adjustable
thermostat so you can fine-tune the temperature of the water.
- Consider purchasing a heater with a built-in thermostat: Some heaters have a built-in
thermostat that allows you to set the desired temperature and automatically turn the heater on
and off to maintain the desired temperature. This can be a convenient feature, as it eliminates
the need to monitor and adjust the temperature manually constantly.
You can follow the table bellow for reference, but remember, it is always better to err on caution and
get a slightly larger heater than you think you need. This will ensure that your tank stays at a consistent
and appropriate temperature for your fish and plants.
|5° C / 9° F||10° C / 18° F||15° C / 27° F|
|5 Gallon/20 Liter||25 watt||50 watt||75 watt|
|10 Gallon/40 Liter||50 watt||75 watt||75 watt|
|20 Gallon/75 Liter||50 watt||75 watt||150 watt|
|25 Gallon/100 Liter||75 watt||100 watt||200 watt|
|40 Gallon/150 Liter||100 watt||150 watt||300 watt|
|50 Gallon/200 Liter||150 watt||200 watt||two 200 watt|
|65 Gallon/250 Liter||200 watt||250 watt||two 250 watt|
|75 Gallon/300 Liter||250 watt||300 watt||two 300 watt|
Using and Maintaining Aquarium Heaters
Using an aquarium heater is relatively simple. Once you have chosen the right size heater for your tank
and set the desired temperature, you need to place it in the tank and plug it in.
It is important to regularly check the temperature of the water in your tank using an accurate
thermometer. This will allow you to ensure that the heater is functioning correctly and that the water is
at the desired temperature.
In addition to checking the temperature, it is essential to maintain your aquarium heater regularly. This
includes cleaning the heater and checking for any signs of damage. If the heater is not functioning
correctly, it may not be able to adequately heat the water in your tank, which can be harmful to your
In conclusion, aquarium heaters are important equipment for maintaining a healthy and comfortable
environment for your fish. They are necessary for keeping the water at the proper temperature, which
can affect the health and behavior of your fish. There are many different types of heaters available on
the market, so it is essential to do your research and choose one that is suitable for the size of your tank
and the needs of your fish. It is also important to follow the manufacturer’s instructions for installing
and maintaining your heater to ensure it works properly and safely. Overall, an aquarium heater is a
necessary investment for any aquarium owner looking to provide the best care for their fish.