2018’s Best Aquarium Heater Reviews: Submersible With Thermostat

best aquarium heatersYou may be wondering, do Bettas and other tropical species need a heater?  Having a good aquarium heater is absolutely essential if you live in a cold place like Canada or Northern US.  Neglecting to get an aquarium heater or getting a poor quality one can have fatal consequences, so we have some recommended products for sale down below to help you with your decision.

A lot of people neglect to account for the temperature changes that can occur in their fishtank.  Just because the water starts out at the perfect temperature doesn’t mean that it will stay that way.  When you buy a top rated fish tank an aquarium heater will act like insurance for your pet fish.  In cold climates a change in temperature can be fatal for your pet so it’s important to maintain the temperature.

Another reason is that certain types of fish need to have the water temperature warmer than the room temperature.  If the temperature isn’t correct for certain species then they can get stressed and their health can deteriorate or worse.  These temperature changes can happen very fast which is a reason that large fish tanks are better than mini ones for newer aquarists, as it will give more time to fix any mistakes that may occur and save your fish. Check out our best aquarium heater reviews below and save your fish from temperature fluctuations.

Top Rated Fish Tank Heaters – Great for Bettas

Here are a few of what we consider to be the top aquarium heater brands on the market today.  We have chosen these based on our usual criteria of a cheap price, durability, and rating.

1. Fluval E Electronic Heater

This is a reliable, fully submersible 300W heater that can handle a whopping 100 gallons of water in the 68-93 degree F range.  There are a couple models and the 50 gallon one can be used for up to 15 gallons of water.  The setup is very easy and can be set at different angles although not horizontally.  The digital LCD display can be set at both Celsius and Fahrenheit too.


  • Nice LCD display
  • Temperature can be set in 0.5 degree increments with great accuracy
  • Has an auto shutoff feature
  • There is a fish guard which stops your fish from coming in contact with the heating element, as well as stopping bigger species from damaging it
  • Fluval is a reputable brand


  • The warranty can be voided if it is set up horizontally
  • A few steps to follow for setup

2. Eheim Jager Aquarium Thermostat Heater

This product by Eheim is submersible and measures in at 1.4 x 19.9 inches. It is recommended to be set up horizontally.

There are 9 different products available that come in different wattages all the way from 25 and 50 up to 300.  The 300 watt model can use up to 150 gallons but the recommended ratio is 5 watts for every gallon of water.

The 25 gallon model is known as being one of the best betta fish heaters as it can heat water in small 7 gallon tanks up to 78 degrees F.


  • The glass is shock resistant and shatterproof
  • The tru-temp dial will stay within 0.5 degrees of the desired temperature
  • Will automatically shut itself off if the water level gets too low
  • Great durability and strength
  • Indicator light shows when it is on


  • Can be a bit difficult to setup

3. Aqueon Pro Heater

This aquarium heater by Aqueon measures in at 4 x 14 x 2 inches and is available in 5 different wattage’s.  The 250W model is capable of raising temperatures to 15 Degrees F above room temperature when used in a 90 gallon tank.  Setup is fairly straight forward and you’ll want it to be horizontal so that you can see the temperature setting.


  • Awesome lifetime warranty!
  • It is designed so strong that you will probably never need to use the warranty
  • The thermostat is electronic so it is very accurate


  • Customer service has been reported to be hit or miss

Types of Aquarium Heaters

When it comes to buying a heater for a saltwater or freshwater tank there are a few different types to choose from like titanium or glass depending on where they will be used.  Each has its own positives and negatives that we will go over below.

Submersible Aquarium Heaters

The submersible type is very efficient because it can be placed right in the water in any position that you want.  You need to make sure though that you leave adequate space around it because your fish could become trapped between it and the gravel or the tank side.  Also, make sure that the submersible aquarium heater never touches the gravel or the glass can crack because of the difference in heat conductivity.

Immersible Aquarium Heaters

temperature regulationThis type which is commonly called a hanging heater is very common because it can be hung over the top edge of a tank and a glass tube that does the heating is put in the water.  Another reason that it is such a popular choice for beginners and a staple in most aquarium kits is that it is very affordable.

In order to use this type of aquarium heater, you must take precautions and secure it so that the glass sheath can’t be bumped into and broken.  The consequences of the glass breaking can be fatal as it can start a fire or even electrocute your pet fish.  Also, this type is not to be used for marine or brackish aquariums because if salt gets into the tube then it will cause corrosion and short out the electricity.

You will need to make sure that your aquarium hood can accommodate this as well, although most will have a good sized opening for this.


Some filters actually come with their own built-in heater which is very convenient.  However, you’ll need to ensure that the filter keeps your water temperature correct.


Sometimes the aquarium heater is actually in the sump which makes it easy to maintain, although the sump requires a bit more space.

In Line

This heater is external and involves the filter or sump.  It is good for bigger aquariums because it is inline between the sump or filter and the tank.  The setup can be complicated at times but does stop the fish and the heater from touching which is crucial.


This type of heater is far more common in Europe than the US.  The way it works is that the heating element is buried under the gravel and then the heat uses the warm gravel to heat the water.  This type is recommended for planted tanks.

In conclusion, buying an aquarium heater can be a must for some people.  We hope that you were able to find one that fits your needs.