What is the Best Underwater Heater for Turtles?

Are you looking for the best underwater heater for your turtle?

Are you unsure of what exactly to look for, and what exactly you need in an underwater heater?

If so, this article is going to clear up these questions and more.


Why Your Turtle Needs a Water Heater

turtle basking platform ideas main

Turtles are mostly aquatic creatures and as such, spend the majority of their lives in the water.

However, they occasionally need to step out of the water and lay in the sun to bask.

  • it dries their shell out to prevent harmful fungi and bacteria from them 
  • it heats up their bodies again, and is also a preventive measure against bacteria, sickness, etc. 
  • they need the sun's ultra-violet rays, especially UV-A and B rays to regulate their metabolism, for their vision, breeding, mood, etc.

Basically, turtles bask to heat up and stay in the water to cool down.

However, if the water that they spend the majority of their time in is too hot or too cold, it can have harmful consequences

If the water is too hot or too cold:

  • water that is too hot will discourage them from basking, and can lead to too much turtle shell shedding, as well as developing harmful fungi and bacteria
  • water that is too cold will discourage them from eating, slow down their metabolism too much and they can easily develop respiratory infections, which are often fatal

Thus, if you want your pet turtle to remain healthy and vibrant, you will need to make sure the water temperature in your tank or tub is not too hot or not too cold.

For the vast majority of common turtle species, the water temperature should be between 72 and 80 degrees.

The basking area should be about 10 degrees hotter than that.

Now that you know why a turtle needs an underwater heater, let's move on to the various types of heaters.

Types Underwater Heaters for Turtles

There is more than one type of underwater heater for turtles.

That being said, they all generally function in the same way, to heat the water, albeit there are advantages and disadvantages to each.

We'll briefly describe what each is, as well as some pros and cons to each, moving from the most common underwater heaters to the least.

Submersible Aquarium Heaters

best underwater heater for turtles
  • usually rod shaped and placed entirely beneath the water, usually vertically or horizontally
  • cheap
  • efficient and can quickly heat water
  • can be moved to a variety of places inside the tank 
  • usually produces very accurate readings of water temperature
  • cannot be placed too close to substrate
  • have to be careful where placed, animals can be burned

Aquarium Substrate Heater

substrate heater
  • work by placing the heater underneath the gravel, sand or other substrate and heating by coil
  • better for larger tanks with lots of gravel and plants
  • maximizes in tank space
  • ​very inefficient heating method
  • more expensive

In-Filter Water Heaters

  • the water heater is placed inside the filter (usually canister) and works by heating up the water as its being cleaned and poured back into the tank
  • maximized in tank space
  • more expensive, as cheap models are very poor quality

On top of submersible, substrate and in-filter water heaters there are also hanging and in-line heaters, however typically these are either much, much less common or only for very expensive tanks with plumbing.

Now that you know about the different types of underwater heaters, let's move on to the best underwater heater for turtles.

The Best Underwater Heater for Turtles

For the vast majority of pet turtle owners out there, a submersible water heater is probably going to be the best choice.

For a few reasons:

  • they are cheap 
  • they are easy to set-up, clean and remove
  • their internal thermometer typically renders a very accurate reading

However, before you go out and just pick any submersible water heater, you will need to figure out one thing.

The wattage.

Here's an easy way to figure out the highest number of watts your heater is going to need.

Allow for 25 watts for every 10 gallons per 10 degree temperature difference.

If you have a 55 gallon tank:

  • 55 divided by 10 = 5.5
  • 5.5 times 25 = 137.5 watts

Thus, if your room is 62 degrees and you want the water temperature in your 55 gallon tank to be 72 degrees, you will need a water heater that is at least 137.5 watts.

If your room was 52 degrees and you wanted the water temperature in your 55 gallon tank to be 72 degrees, you will need a water heater that is at least 275 watts.

What does all this mean?

The more watts in the water heater, the better, particularly if you live in colder climates.

Below is a table of the best submersible water heaters.

NameWattsStars & ReviewsPriceFeaturesLink
EHEIM Jager Aquarium Heaterwhat's the best underwater heater for turtles main25-3004.3 stars & 1,026 reviews$-$$Automatic off switch when water level too lowClick Here
Aqueon Pro HeaterAqueon Pro Heater50-2504.5 stars & 881 reviews$-$$Shatterproof, for fresh and saltwaterClick Here
Tetra HT Submersible Heatertetra underwater heater5-2004 stars & 888 reviews$Light turns red when heating, green when temperature reachedClick Here
Finnex Titanium Hang-on Heaterbest underwater heater for turtles100-5004.5 stars out of 174 reviews$$-$$$High wattage, outside dial to easily change temperatureClick Here

Finnex Titanium Hang-on Heater

best underwater heater for turtles

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This tops our list as our best underwater heater for turtles, for a few reasons. Let's quickly go over the benefits and advantages.

  • 100-500 watts, which means it can easily heat tanks that are over 100 gallons
  • Titanium, shatterproof tube to prevent cracking and breaking
  • adjustable from 70-92 degrees, in increments of 2 degrees
  • analog controller sits outside your tank, so you don't need to stick your hand in the water as with other underwater heaters
  • for both salt and freshwater
  • LED heating indicator to let owners know when the device is working and when the correct water temperature has been reached

EHEIM Jager Aquarium Heater

what's the best underwater heater for turtles main

Click Here for More Info

The EHEIM Jager Aquarium Heater is also another solid choice. Though we wouldn't place it at the top of the heap with the Finnex, it's nearly as good.

Benefits and advantages:

  • 25-300 watts
  • Automatically turns off when the water level becomes too low or the device overheats
  • Shock-resistant and shatterproof glass
  • adjustable temperature dial

Aqueon Pro Heater

Aqueon Pro Heater

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The Aqueon Pro Heater is an overall solid device, with tons of positive reviews which laud it's longevity and efficiency. It's benefits and advantages:

  • 50-250 watts
  • For fresh and saltwater
  • Shatterproof
  • Electronic thermostat

Tetra HT Submersible Heater

tetra underwater heater

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Rounding out our top four picks for the best underwater heater for turtles is the Tetra HT Submersible.

It's benefits and advantages:

  • 50-200 watts
  • Cheap
  • Super-easy to install
  • Indicator light to let you know when the device is on

Overall, all four of these picks would be wise, depending on the size of your tank and wattage needed. For larger tanks, the Finnex is really ideal, however if you are going a little bare bones the Tetra HT is also a solid choice.

Hopefully, this article cleared up any questions you may have had about what is the best underwater heater for turtles. As always, feel free to drop us a line below!


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