What size heater do I need for my Aquarium?

How Do Aquarium Heaters Work?

 Aquarium heaters convert electrical energy into heat. Over time, the heater increases and maintains the temperature of your aquarium. 

Watts are a measure of how much energy an aquarium heater generates. The higher the wattage of a fish tank heater, the higher the temperature increase that can be produced. 

What Size Heater Do I Need For My Aquarium?

You can easily work out the ideal heater size or your aquarium by first working out the volume of water held in your tank.

How Do I Calculate Water Volume in my Aquarium Tank?

 To calculate the water volume of your fish tank, first measure the length (in metres), height (in metres) and width (in metres) of your tank:

Volume (m³) = Length (m) x Height (m) x Width (m)

Multiple by 1,000 to convert m³ to litres. 

Example: If your tank measures Length 1.22m, height 0.46m and width of 0.36m, your calculation will look like this:

1.22m x 0.46m x 0.36m = 0.2m³

Multiply 0.2m³ by 1000 = 200 litres.

What Fisk Tank Temperature Increase Do My Fish Need?

Next you will need to work out the maximum temperature increase required to heat your aquarium water to the optimal temperature for your fish. 

Example:Assuming you live in Melbourne, with an aquarium inside, your temperature might dip to 15 °C in winter. For tropical fish, this is at least 10 °C cooler than they require for optimal health. Therefore, work out your temperature increase:

25°C  - 15°C = 10°C 

Temperature Table:

 If the exact size heater you require isn’t available, it’s always better to install a heater that is too large rather than one which is too small. A heater which is too large will quickly and efficiently heat your aquarium water, switching off once the ideal temperature is reached. However, a heater that is too small, will take much longer to reach the desired temperature and it many cases may not reach it at all. A heater that is too small is therefore inefficient and often unliable. It will also, in the long run, cost you more to run. 

In case of heater failure, it’s ideal to have a second, back-up heater ready to install. Therefore if your existing heater fails, you can immediately install your back-up heater and avoid the risk of endangering your fish or plants. 

With the above guide, you’re well on your way to equipping your fish with the ideal temperature and environment needed to help them thrive!