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What is an Aquarium Temperature Controller
A temperature controller is a separate device, independent of your aquarium heater, to control the temperature of your aquarium. They usually have three main components:-
- The Controller – Used to set your desired temperature and record the current temperature. Some controllers require you to set them manually using the buttons on the device whilst others are wi-fi enabled and can be set up using an App.
- Temperature Sensor Probe – the probe is placed in the water measuring the temperature which is then displayed on the controller. Some temperature controllers have more than one probe and you can also get non-metallic ones for use in saltwater tanks.
- Plug Socket – into which you can plug your aquarium heater or heaters if you have more than one.
How do Aquarium Temperature Controllers Work
Once the desired temperature has been set, the controller monitors the temperature in the aquarium using the probe, and once that temperature is met it switches off the power to the plug socket, thereby turning off the aquarium heater.
When the temperature in the aquarium drops below the desired temperature, the controller powers up the plug socket again which turns the aquarium heater back on.
Why Use an Aquarium Temperature Controller
As our tropical fish require a warm environmental temperature ranging between 75 and 80 °F(24 to 27 °C) we set our heaters to that level using the built-in regulator in the heater.
So, why use a separate temperature controller?
The answer is heater failure. Heater failure is the single biggest cause of aquarium failure and a common cause of many fish deaths.
If your heater should fail, the temperature in your tank can drop rapidly, depending on the time of year and ambient room temperature. And it’s not just your fish that may suffer but any plants and corals you may have in your tank.
An alarm set on your temperature controller can alert you to this problem straight away so you can take immediate action.
It’s also the reason most good temperature controllers come with two plug sockets, to allow for two heaters, so if one fails the other one will stay on and keep the tank temperature at the desired level.
Aquarium heaters can also fail ON. That is, they reach the desired temperature, fail, and stay turned on, which will rapidly overheat the water and kill your fish!
A temperature controller stops this as all power to the heater is turned off once the desired temperature has been reached.
Types of Aquarium Temperature Controllers
- Heating Controllers – control solely the heating up of the aquarium as described above. They can have one or more plug sockets and be manual or wi-fi controlled.
- Heating and Cooling Controllers – can also control a plugged-in fan or chiller that would be powered up if the temperature in the aquarium got too hot.
Conclusion
We definitely recommend using a temperature controller for the reasons outlined above. We also recommend using two heaters so that if one fails, the other will keep your tank temperature stable.
We also love the wi-fi versions but the manual ones do the job just fine.
Take a look at our guide, Best Aquarium Temperature Controllers for more information.
Temperature Controller On Your Aquarium FAQs
How do aquarium temperature controllers work? – The required temperature is set on the controller which then monitors the temperature in the aquarium using a temperature probe. When that temperature is met the power to the plug socket is turned off, thus turning off the aquarium heater.
When the temperature in the aquarium drops below the required temperature, the controller turns the plug socket on again which then turns the aquarium heater back on.
Where is the best place to put a temperature probe in a fish tank? – Place the temperature probe as far away as possible from your heater. That way you can be sure that the temperature you desire for the whole tank is reached.
In a saltwater tank with a sump, the heater(s) should be in the sump and the temperature probe in the display tank.
What is the set point of a temperature controller? – The set point of a temperature controller is your target temperature. So, if you wish your tank water temperature to be 79 degrees F then that is your set point.