An aquarium temperature controller is a fail-safe device that sits between your aquarium heater and your electrical wall outlet.
They not only control the temperature of your aquarium but also protect it from any potential heater failures.
An aquarium temperature controller can also be used to keep an aquarium cool in hot weather.
Sensors in the aquarium alert the controller as to the current temperature so that it can regulate when heaters, fans or chillers are activated.
Table of Contents
Top 5 Aquarium Temperature Controllers
| # | Preview | Product | Quick Review |
| 1 |  | Inkbird Digital Aquarium Temperature Controller | Best Overall |
| 2 |  | D-D Dual Aquarium Heating & Cooling Controller | Good |
| 3 |  | Ketotek Digital Thermostat Temperature Controller | Does the job |
| 4 |  | Digiten Temperature Controller | Freshwater Only |
| 5 |  | Hygger Aquarium Heater with LED Digital Temperature Controller | Limited Use |
Why You Should Use an Aquarium Temperature Controller
Heater Failure – No matter what aquarium heater you have, they can fail and an aquarium temperature controller will alert you quickly if this happens.
Heaters can also fail ON. That is, they fail to turn off when they have reached the set temperature. This can literally cook your fish.
This can’t happen with an aquarium temperature controller as all power to the heater is switched off when the set temperature has been reached.
Temperature Alerts – with a temperature controller you don’t just have to wait until you, or your fish, notice the water has cooled, you get an alert.
Keeping Your Aquarium Cool – if you have hot summers or live in a tropical climate you may wish to automate keeping your aquarium cool. You can do this by attaching a fan or chiller to an aquarium temperature controller.
What to Look for When Buying an Aquarium Temperature Controller
Heating or Cooling – If you need to do both be sure to get an aquarium temperature controller that has this functionality.
Fresh or Saltwater – Check that the temperature controller has plastic-coated non-metallic probes. Metal probes will corrode in saltwater.
Wi-fi Control – If you wish to control the temperature controller via Wi-Fi make sure its Wi-fi enabled.
Best Aquarium Temperature Controller Product Reviews
Here are my reviews of the beat Aquarium Temperature Controller products:-
1. Inkbird Digital Aquarium Temperature Controller
The Inkbird Digital Aquarium Temperature Controller is probably the most versatile on the market.
Depending on the version you get Inkbird Temperature Controller can:-
- Control both heating and cooling
- Add one or more heaters
- Have one or two temperature sensor probes
- Temperature sensor probes for both freshwater and marine aquariums
- Manual or Wi-Fi control
Set a range of temperatures for your aquarium and the controller will ensure they are kept stable. Audible and visual alarms can be easily programmed.
On the Wi-Fi versions, everything can be controlled remotely via the app, which also includes graphs and alerts.
Pros
- Can control both heating and cooling (version dependant)
- Visual and audible alarm
- Freshwater or Marine (version dependant)
- Wi-Fi (version dependant)
- Easy set-up
Cons
- Slightly confusing number or versions available
2. D-D Dual Aquarium Heating & Cooling Controller
The D-D Dual Aquarium Heating & Cooling Controller has two plug outlets, one for heater control and one for fan/chiller control.
Set a range of temperature for both and keep your aquarium temperature stable in all conditions.
An alarm (audible and visual) can be set at low and high temperature extremes to alert you of any issues.
The single plastic-coated temperature sensor can be used in both marine and freshwater aquariums
Pros
- Controls both heating and cooling
- Visual and audible alarm
- Freshwater or Marine
- Accurate temperature control
Cons
- No Wi-Fi
- Only one sensor
3. Ketotek Digital Thermostat Temperature Controller
The Ketotek Digital Thermostat Temperature Controller has a dual relay output, one for heating and the other for cooling.
It will automatically turn your heater and/or cooler on/off as programmed to keep the temperature within the desired range with an accuracy of ±1℃.
Set high/low temperature alarm value, when the temperature exceeds the alarm value, the alarm indicator will flash and the buzzer alarms.
The temperature sensor can be used in both marine and freshwater aquariums
Pros
- Controls both heating and cooling
- Temperature and sensor fault alarm
- Freshwater or Marine
Cons
- No Wi-Fi
- Only one sensor
- Fiddly set-up
4. Digiten Temperature Controller
The Digiten Temperature Controller comes with 2 sockets output, one for heating and another one for cooling.
Includes an over and under-temperature and sensor fault alarm.
The single metal temperature sensor can really only be used safely in freshwater aquariums
Pros
- Controls both heating and cooling
- Audible alarm
Cons
- No Wi-Fi
- Freshwater Only
- Only one sensor
- Fiddly set-up
5. Hygger Aquarium Heater with LED Digital Temperature Controller
At first glance, the Hygger aquarium heater looks like any other aquarium heater with a separate digital display and controller.
But notice that the heater is not directly plugged into the wall outlet but into the display controller (which is then plugged into the wall outlet). So the display controller controls the power to the heater and not just the temperature setting.
This means that when the desired heat has been reached the Hygger stops all power from getting to the heater.
So if the heater failed ON then the aquarium could not overheat as the heater would have no power.
Pros
- Combined heater and controller
- Relatively cheap
Cons
- Low quality heater
- Only one plug outlet
- No option for cooling
- Limited alarm function
Conclusion
The Inkbird Digital Aquarium Temperature Controller gets our vote as the best aquarium temperature controller for its sheer versatility.
There’s a version for every type of aquarium and requirement from a temperature controller.
The Wi-fi App is excellent and we’d definetely recommend getting a Wi-Fi enabled version.
Aquarium Temperature Controller FAQs
Will a temperature controller alert me when the temperature gets too hot or cold? – Yes, although some temperature controllers just flash, most will give an audible beep to alert you. Wi-fi enabled temperature controllers will also alert your smartphone via an app.
Can I use a temperature controller to keep my aquarium cool in the summer? – Yes, provided you get one with a cooler option that plugs into a fan or chiller. You can set a minimum temperature which, when reached, will turn the heater on, and a maximum temperature which, when reached, will turn the fan or chiller on.
Can I use a temperature controller in my saltwater tank? – Yes, provided you get one with a non-metallic probe. Saltwater will corrode a metal probe over time potentially leaching harmful elements into your tank. So, be sure to get one with a plastic-coated temperature probe.