5 Best Aquarium Heater Controllers

It is essential to keep your fish at an appropriate place where light, noise, and temperature is suitable for your fish.

I did not have any idea about this initially when I brought my little fishy friends home.

But yes we learn from our mistakes and so did I.

As my fish family grew, I started taking care of these things more than ever.

Our Top Picks

Hygger Submersible Aquarium HeaterTotally submersible
Inkbird Pre-Wired Dual Stage Digital Temperature ControllerNon-submersible
RANCO ETC-111000 Digital Cold Temperature ControlNon-submersible
Aqueon Pro SubmersibleTotally submersible
Hydor In-Line External HeaterNon-submersible

What is an Aquarium Heater Controller?

Basically, an aquarium heater is a device used to warm the water in the aquarium.

Unlike humans and other mammals, fish don’t produce their own body heat. In that case, it is your responsibility to maintain the proper temperature of your aquarium.

If you own fish especially a tropical fish, then remember to buy the heater too.

Fish and Fish Tank Heater

The optimum temperature for your aquarium depends on what type of fish you own.

As one temperature doesn’t suit all types of fish.

Some fish fare better in a more warm temperature while some prefer a cooler environment.

So it is important to KNOW YOUR FISH.

Do proper research, and if you are keeping only one kind of fish then maintain the temperature which your fish requires.


If you are a hard core fish lover and have different kinds of fish in one aquarium, then the temperature for that aquarium should be around  80°F which suits almost all fish

But again, try your best not to keep different types of fish in the same tank if you cannot handle it properly

Types of Aquarium Heaters

There are four types of heaters for aquarium

1. Submersible heaters

2. Immersible heaters

3. Substrate heaters

4. Filter heaters

Heat Controllers for Aquarium

In order to provide your fish with a healthy environment, you have to take care of many things.

Such as placing a proper heat controllers in your fish tank.

For different aquarium sizes, there are different heaters available.

So before buying a heater consider the size of your aquarium.


Having the proper information will help you choose the best of all heaters

Detailed Product Description

Hygger Submersible Aquarium Heater, Adjustable Fish Tank

I am in love with this product.

It is made up of heat resistant quartz tube because of its different size range.

There are a total of 3 sizes 50W, 100W and 300W available.

For 7-10 gallon fish tank, the 50W heater is best.

The length of the heater is 7.5 inch.

For 10-30 gallon tank, 100W is suitable, and the length of the heater is 8.5 inch

Whereas For 30-60 gallon fish tank, the 300W heater is appropriate and the length is 10.6 inch

In order to use it, all you have to do is place it entirely in the water, when the heater is heating the tank the red light on the LED is on, and when it is off means the heater is not working.

The temperature controller is placed outside the aquarium, and you can adjust the temperature by rotating the pointer.

The built-in thermometer in the heater detects the water temperature.

This heater, if used correctly can last for 3 years.

The package includes 1 aquarium heater, 2 suction cups that can stick to the tank, user manual, and 1 shield.


  • Hygger Submersible Aquarium Heater is made both for freshwater and saltwater
  • it is easy to install
  • Temperature is easy to set
  • This submersible heater is long lasting


  • The heater can only be placed horizontally
  • It can not be placed in a tank if there is turtle
  • You cannot keep it under stones

Inkbird Pre-Wired Dual Stage Digital Temperature Controller Outlet Thermostat

ITC is much more expensive than the Hygger Submersible Aquarium Heater.


With more price, comes more benefits.


ITC is a multi-purpose and multi-functional product, that is, can be used as a heater and a cooler

It can be connected to both refrigeration and heating equipment.


the best thing about this product is that it can be connected to both at the same time

With that, it can be used as an automatic temperature controller for different devices.

A high and low-temperature alarm is also present.

The dual display window can display both measured temperatures and set the temperature at the same time.

When the probe temperature gets below the set point, the outlet heater turns on.

When the probe temperature rises, the outlet heater stops.

The package includes a temperature controller and a manual.

It can give readings both in Centigrade as well as Fahrenheit unit


  • ITC-308 Easy to use.
  • It is safe and reliable because of sensor fault alarm
  • Digital display
  • It depends on the equipment you want to control


  • Wiring and assembling
  • A bit expensive
  • The heater and cooling outlet are very close to each other because of this large plugs can not be fitted in at the same time

RANCO ETC-111000 Digital Cold Temperature Control NEW

The RANCO ETC is a rectangular shape product which is 6.25 inch high, has a digital display.

The controller is easy to install if the instructions are correctly read.

Easy to adjust the temperature, within 1 degree.

RANCO ETC-111000 can be used for a wide variety of applications.

There are two stages that are individually programmable for cooling.

So it works in a pretty good way.

When the temperature rises or falls according to the set temperature, the device cuts off the power.

When the temperature deviates from the set range, the device turns on.


  • RANCO ETC-1000 is easy to program
  • Wiring is easy
  • The thermostat is accurate to a large extent


  • Sometimes the product fails to work for a long time.
  • Some might fail after the first use.

Aqueon Pro Submersible 100W Heater

Image result for Aqueon Pro Submersible 100W Heater

This heater, provides 100W and is 10.37 inches long.

It’s fully submersible and can be placed horizontally as well as vertically.

The Aqueon pro heater is suitable for both freshwaters as well as salt water fish tanks.


When the heater overheats, it automatically shuts off, and when cools down it turns on.

The red light on the heater indicates that it is heating and the green light indicates that it is not heating.

The heater has electronic thermostats which is beneficial for accurate temperature settings

Aqueon pro submersible heater’s range is between 68 to 88° F

The guideline chart can help you to see 100W suitable for your tank, depending on how much temperature you want to raise above room temperature

Mostly 100W is suggested for 20-gallon fish tank.

Hydor In-Line External Heater – Original ETH

In-line aquarium heaters are basically placed outside the aquariums

Hydor In-line external heater is suitable for both freshwater and tropical aquariums.

It is not submerged in the water, instead it is placed outside the aquarium

It is easy to install, and there are many videos you can watch to learn how to install it.

Because of the presence of positive thermal coefficient (PTC), hydor In-line external heater performs the heating tasks differently.

It is designed in a way that one cannot see what is inside, actually inside it is the glass tube through which water passes, that water is heated by the heating element around the glass tube

The knob or rotatory can help you set the desired temperature


  • It is easy to use.
  • Temperature of aquarium is maintained
  • Doesn’t overheat the aquarium because of the presence of positive thermal coefficient PTC
  • Saves space


  • Built-in thermostat may fail
  • Not really durable

Fish Tank Size and Heater

Although you require a heater and the temperature that is appropriate depends on the fish you own

The size of your fish tank is also relevant while buying a heater.

There are different sizes of heater available for different gallons of fish tanks

Importance of a Heater

Cold water can bring as much disaster to your fish tank as very hot water would.

The sudden change in temperature can be problematic to a very large extent.

As winter approaches the temperature of your house drops.

Similarly the temperature of the aquarium also drops which can be dangerous for your fish family.

There are some heating challenges that you would have to deal with, like heater breakage

In summer months you have to take totally opposite preventive measures due to the high temperature of water.

For better results I will suggest you to place the heater near the water inlet or outlet or in other words place the heater where there is more water flow than other areas.

Monitor the Temperature

After installation setting of the heater, you have to watch the temperature. It can take a few hours to 48 hours to give the desired temperature.

Increase the temperature of the heater if the temperature of the water is not raising

Lower the heat if it’s increasing the water temperature too much


Some heaters have simple adjustments like warm and cold.

 In that case, you have to warm the water until it is done or vice versa

While others have degrees, you can just set the desired temperature and it will either increase or decrease the temperature of your aquarium to reach the set temperature.

Appropriate Temperature For Different Fish.

Tropical fish generally survive in warm water.

For them a heater is important, especially in winters otherwise they will die in the cold water

The best part about most heaters is that they turn off automatically when the desired temperature is obtained

The temperature of water for tropical fish should be at least above 74 degrees Fahrenheit.

While on the other hand, non-tropical fish can survive in cold water

So if you are a beginner and don’t want a heater.

 Then go for fish which can survive in room temperature water like gold fish

Goldfish can handle colder temperature.

Different fish species and preferable temperature

Whitefish     55  °F 
Lake trout         53  °F
Guppy     75  °F  
Rainbow trout     55  °F  
Pink salmon      55  °F  
Brown trout      60  °F  
Yellow perch     64  °F  
bluegill         86  °F  

What to Do In Hot Weather?

Cold water can be dangerous to your health.

 In the same way, hot water can be hazardous for the fish.

Here are some tips to keep your fish safe.

In hot weather, increase the water flow.

At high temperatures, fish require more oxygen.

So moving water picks up more oxygen and the water cools as well.

Similarly to lower the water temperature, remove the aquarium head and bring a fan close to the water surface.

Some of the water will evaporate.

Now add some cold water as a replacement of evaporated water.

Keep in mind you have to add just a little amount of cold water, or else you will shock your fish.

Secondly, you can freeze plastic bottles and keep it in tank.

This technique helps a lot


Don’t keep a big bottle because that will change the temperature very quickly and such quick temperature change can be very much dangerous and harmful for your fish.

If you have placed the aquarium at a place where the temperature is mostly high, then you will need a chiller for the fish tank

Some of them can be placed directly inside the aquarium like coils

While some are placed outside the aquarium.

It works in a simple way

Water flows from aquarium through the chiller and then back to the aquarium


For better understanding do read the instructions properly

When purchasing a heater check the thermometer, especially if you are buying a used one.

Though most of the heaters are waterproof because they are fully submersible, some are not.

 So you should take care of the heater or to be on the safe side, go for a submersible heater

As there are some adjustable heaters, using which you can adjust the water temperature.

Better look for such heaters.

Do consider your room temperature while buying a heater.

Buy a product made up of high-quality material

Find a suitable location to place your heater

Other Important Things For Fish Tank

Apart from the heater, filters, gravel, air pump, decorations, and fish food are important

And yes do not forget to add fish too…

Related Questions

How many filters are there? Biological, chemical and mechanical, there are three types of filtration. Biological filtration is concerned with fish waste. Chemical filtration works to remove the ammonia etc. And mechanical filtration traps particles such as leaves etc.

How many fish can you have in your aquarium? Generally, it’s better to have 1-inch fish for at least 1 gallon of water. 2 or 3 gallons would be appropriate.

How long can fish stay alive without being fed? You might be away from home and cannot feed your fish. Don’t worry. Unlike humans, fish do survive even without being fed for a week or 2.

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