The Best Aquarium Heaters (Selecting the Best & Designing A Heating System)

November 19, 2018

Best Aquarium Heaters

Aquarium heaters are one of the more essential, yet more fail prone piece of equipment that you can add to your aquarium. The vast majority of us in the aquarium keeping hobby keep fish that require tropical temperatures so a heater is a must.

There are many heaters out on the market and it is very easy to just select a cheap aquarium heater and think you are good to go. The best aquarium heaters are not fail prone, built very well, and will heat your aquarium safety. I will go over the best aquarium heaters and also talk about glass vs titanium heaters. I will also talk about fail safes and how to prevent a tank disaster if a aquarium heater fails (and also what usually fails). Let's get started!

Benefits of an Aquarium Heater

Because most of us in the fish keeping hobby keep tropical or saltwater fish, they require temperatures to be consistently around 75 - 80 degrees Fahrenheit (or 24 to 27 Celsius. Since we keep aquariums indoors in our home, most people would think that the ambient temperature of our home could keep our aquariums at a safe temperature. However, seasons change and there are certain times like in the winter where temperatures in your home can drop below 70 degrees or less in your home putting our precious livestock at risk.

The best aquarium heaters not only keep your temperature up, but are easily adjustable so you can set the temperature to what you need it to be. They are also accurate to boot. Some will even come equipped with a separate temperature controller so you add redundancy in the event a heater fails.

Best Aquarium Heaters on the Market

There are many heaters out on the Market. The list below were handpicked by our years of experience in the hobby and through various client builds. They all have their strengths in particular setups which we will explain below.

Picture Name Best For Links
No. 17 Small Submersible Heaters  Small and Nano Tanks

Aqueon Pro Adjustable Heater All setups

Cobalt Aquatics Accu-Therm Heater Cobalt Aquatics Accu-Therm Submersible Heaters All setups


Cobalt Aquatics Neo-Therm Heaters Cobalt Aquatics Neo-Therm Heaters All In One Tanks, Reef Tanks


Finnex Deluxe Titanium Heater Finnex Deluxe Titanium Tube Heater with Guard Large Freshwater & Saltwater Tanks


Finnex Digital Touch Control Aquarium Titanium Heater Guard Finnex Digital Touch Control Titanium Heater All setups

Ehiem Jager Heaters Eheim Jager Aquarium Thermostat Heater All setups

Hydor Inline Aquarium Heaters Hydro In-Line External Heaters Aquariums with Canister Filters

Hyggar Titanium Aquarium Heater Hygger Titanium Tube Submersible Heater with Controller Budget Aquarists who want a controller

Best Aquarium Heaters Review

1. No.17 Small Submersible Heaters - Compact Aquarium Heater Ideal for Smaller Tanks

No.17 Small Submersible Heaters

If you are OCD like me and don't have a sump or all-in-one tank with chambers to hide your heater, the No.17 small submersible heaters offer a heater that is compact and easy to hide in your aquarium. The high Quality quartz glass design provides a shatterproof construction.  The LED display on the heater itself gives you a temperature reading if you want to place it on an area where you can read it. It does have a sleek design, making it easy to hide in rock work or have it visible but still look nice in the aquarium.


  • Small design
  • Quartz design makes it shatterproof
  • LED reads temperature


  • New player on the market
  • No separate controller for redundancy
  • Best for smaller aquariums

2. Aqueon Pro Adjustable Heater - An Aquarium Heater with Limited Lifetime Warranty 

Aquaeon Pro Adjustable Heater

A shatterproof adjustable heater with a limited lifetime warranty. That sounds like a great heater and rightly so on this list. Aqueon has been in the Aquarium industry for a long time and many of us have trusted them for our tanks as many of the standard tanks old these days are manufactured either by Aqueon or Marineland. 

The Aqueon Pro Adjustable Aquarium Heater comes with a temperature dial that is painless to adjust. Because it's a manual control, it is less prone for its temperature configuration to fail because the setting will not reset during a power outage. It is accurate within 1 degree, which is adequate for most setups, but would be considered suspect in a delicate environment such as a reef tank.


  • Lifetime warranty and Aqueon Name
  • Manual temperature dial that will not reset in a power outage
  • Shatterproof design


  • Only accurate up to 1 degree
  • No separate controller for redundancy

3. Cobalt Aquatic Accu-Therm Heaters - Computer Tested Accurate Aquarium Heater

Cobalt Aquatics Accu Therm Heaters

The Cobalt Aquatics Accu-Therm Submersible Heaters may not be the prettiest heater on this list, but they offer a computer tested heater for added assurance the the heater will heat to the correct temperature. It is also equipped with an easy to use manual temperature adjustment dial that is will not reset during a power outage. It is constructed of Borosilicate glass, which is more resistance to thermal shock (e.g. - your heater exploding). This glass is what is typically used in lab environments, making this a higher end constructed heater than your typical budget glass heater.


  • Computer tested
  • Lab grade borosilicate glass construction
  • Manual temperature adjustment dial


  • Ugly looking design
  • Accurate up to 2 degrees - A separate controller is must!

4. Cobalt Aquatic Neo-Therm Heaters - The Most Accurate Heaters on the Market

Cobalt Aquatics Neo-Therm Heaters

If you have a system that requires precise constant temperature with sensitive inverts/fish like a reef tank, the Cobalt Aquatics Neo-Therm Heaters can't be beat. Computer tested and accurate up to 0.5 degrees Fahrenheit (better than most controllers on the market in fact), this heater to many in the reef aquarium hobby is the go to.

When the Neo-Therm was first released, it did have a number of quality control issues. There were several early models that exploded in tanks, which has lead to a number of bad reviews. However, Cobalt has addressed the manufacturing issues and now this really is one if not the best aquarium heaters available on the market.

It does come with a higher price tag though. They are one of the more expensive heaters available and they also only come in smaller wattage sizes, meaning you will need multiple units to run a larger tank.


  • Accurate up to 0.5 degrees Fahrenheit!
  • Manual temperature adjustment dial
  • Compact design - fits in all in one systems


  • Only available in smaller wattage
  • Legacy QC issues with early models
  • Expensive

5. Finnex Deluxe Titanium Heaters - The Heater of Choice for Monster Fish Keepers

Finnex Deluxe Titanium Heaters

For those of us with large tanks over 200 gallons, it is difficult to not only find a high wattage heater, but also a heater that is about to take the punishment of large aggressive fish who may trash about in the aquarium and knock down rocks and equipment.

This is where the Finnex Deluxe Titanium Heaters answer the call. It is a titanium built heater, which make them virtually indestructible. A titanium made heater is also more corrosive resistant then glass heaters, making it ideal for saltwater environments. 

It unfortunately does not have a built in way of controlling temperature, which is why this package comes with its own controller. However, because there is no adjustment dial on the heater itself, there is no redundancy on the heater unit to protect against failure. The controller itself is only accurate up to 2 degrees Farenheit, which is fine for freshwater and fish only saltwater setups. Reef tank users will want to consider purchasing the Finnex Titanium Heater Rod only and go with a more accurate aquarium heater controller or utilize a high end controller like an Apex Controller.


  • Titanium built design
  • Comes with a digital controller
  • Available in up to 800W


  • No adjustment dial on heater itself
  • Controller is accurate only up to 2 degrees Fahrenheit 
  • Not available in smaller sizes

6. Finnex Titanium Heaters - Titanium Heaters for the Rest of Us

Finnex Titanium Heater with Digital Controller

Titanium heaters are considered better than glass heaters due to the fact that titanium is more corrosive resistant and are nearly indestructible. Our last heater was only available in high wattage, but this variation of Finnex Titanium Heaters are for the rest of us. With very similar pros and cons, this heater will get you a titanium heating element had a reasonable price.


  • Titanium built design
  • Comes with a digital controller


  • No adjustment dial on heater itself
  • Controller is accurate only up to 2 degrees Fahrenheit 

7. Eheim Jager Heaters - Old Faithful with Legendary Brand Name 

Eheim Jager Heaters

Ah the Eheim Jager Heaters. They have been around seemingly forever and completely unchanged for ages, and there is a good reason why. It is simply a very well built and reliable heater. Quality German made, UL listed electronics, and a manual adjustable heater gauge are it's main features. It is accurate up to 0.5 degree Fahrenheit, making it as accurate as the Cobalt Neo-Therms. It also has the ability to be re-calibrated!

Because it is it a quality manufactured heater, it simply hasn't been updated in years and looks the part. It is big and bulky, it uses old school lab grade glass, and the adjustable dial itself is cumbersome. However, Eheim's legendary name brand is behind it and anyone who has been in the aquarium industry knows the great quality and durability that Eheim manufactured products bring. It's ugly looking and big, but you won't be disappointed using this as your aquarium heater.


  • German made and Eheim name
  • Accurate up to 0.5 degrees Fahrenheit
  • Can be re-calibrated


  • Big and bulky
  • Old school lab grade glass design
  • Temperature dial is a bit clunky

8. Hydor Inline Heaters - A Great Choice For Canister Filter Users

Hydor InLine Heaters

The Hydor Inline Heaters are the perfect choice for aquarists who own a Canister filter. Because this heater runs through your return line, you do not have to worry about this heater being inside of your tank and prone to the abuse some of your fish would cause on it moving rock work or even yourself hitting it accidentally while performing maintenance.  It is constructed with Hydor's patented PTC heating technology. The way the unit works is that it is made of a special polymer that has been printed with aquarium safe ink. This ink heats up the passing current as the water is transferred into your aquarium. It really is a fascinating technology!

It does come with some major drawback though. It must be installed in the vertical position, which can be a problem for those with limited space in their cabinets. It can be only installed with vinyl tubing, making it non-ideal for setups with hard plumbing. Hydor also does not state how accurate the heater is on their specs, which forces me to say a controller is a must.


  • External heater
  • Slick operation and patented technology
  • No risk of heater burn on fish


  • No specs from Hydor on how accurate it is
  • Can only be used with vinyl tubing
  • Only available up to 300W

9. Hyggar Titanium Aquarium Heaters - New Player on the Market Delivering Budget Titanium Heaters

Hyggar Titanium Aquarium Heater

This aquarium heater really surprised us. The Hyggar Titanium Heaters come with a digital controller that claims 0.5 degrees of accuracy. That claim would make it one of the most accurate controller on the market.

They are a unknown brand at this point, but the reviews have been pretty stellar, enough for us to consider them on our list for aquarists looking for an all in one solution titanium heater with a controller.


  • Titanium design
  • Controller claimed accuracy of 0.5 degrees


  • New manufacturer

How to Choose the Right Aquarium Heater

I've provided a lot of choices here and it can be frustrating to figure out which one works best. No worries though, let me help you out.

Size of Aquarium Heater

All the aquarium heaters listed on this blog post come in various sizes. Some like the Eheim Jager are very bulky while the Cobalt Neo Therm Heaters are very compact in size. If you do not have a sump or canister filter, the size of the heater will come into play as it may stick out like a sore thumb. Smaller heaters are easier to hide and also getting multiple heaters will help with hiding them in the tank (redundancy is also another reason to get more than one heater which I'll explain in further detail).

Types of Aquariums

The type of aquarium you own will help determine what heater you will need. For example, if you have a fish only freshwater community tank with most hardy fish, you can likely get by with a single heater and a relatively cheap one.

If you have larger predator fish like Cichlids or Arowanas, you will want a heater that can take a beating. This is where Titanium heaters can come into play as they are virtually indestructible.

For those of us who have sensitive inverts or exotic fish like you may have with a saltwater reef aquarium, accurate and reliable temperature is critical. A swing in temperature could cost us thousands of dollars in lost livestock with such setups. Therefore, as a reef tank owner, it is imperative that we build our heating system with multiple redundancies and safeguards to protect our livestock.

Types of Aquarium Heaters

I did throw out a number of terms when it came to heater construction so I can be a little more detailed here. Most aquarium heaters are constructed of the following materials:

  • Glass
  • High Quality Glass like Quartz or Bososilicate 
  • Titanium

Glass heaters are what you will typically find with value based brands that are not listed on this list. I have completely ignored these because they are prone to exploding in a tank and shattering! Not something you want:

Exploded Heater

Highly quality glass like what you see with the Ehiem and Cobalt Accu Therm heaters are durable glass that is resistant to thermal shock and less prone to exploding like above. They can still crack if dropped or hit by a rock, but it normal operation they should be fine, especially if they are placed in a safe area like a sump.

Titanium heaters like the Finnex heaters are virtually indestructible and great for tanks with larger fish. They also tend to be the most expensive of the lot.

Your Budget for an Aquarium Heater

I have listed a number of quality heaters in this post in all ranges of budgets. Once thing to note is that many aquariums will run multiple heaters and I am aware that not everyone will have the budget to deploy a multiple heater setup. For the best bang for the buck, I feel that the Aquaeon Pro Adjustable Heaters offer the best mix of quality and price.

Where to Place Your Aquarium Heater

It is best place your heater in an area that gets a good amount of flow. This will normally be an area in close proximity to a power head, power filter, or air stone. You also want to keep aesthetics in mind so if you are placing the heater directly into your display, you will want to place the heater behind rock work or plants. 

Placement is even easier with an all in one aquarium as there are compartments available in the return section where you can place your aquarium heater in. If you have a sump, it's even easier can you can place them in your sump after your first chamber.

How Many Watts Does My Aquarium Heater Need to Be?

It is actually a very simple rule of thumb that unfortunately gets confusing if you visit aquarium forums. The rule is 3 watts per gallon of water. So breaking this down this would be:

Tank Size Watts Needed
10 G 30 Watts
20G 60 Watts
29G 87 Watts
40G 120 Watts
55G 165 Watts
75G 225 Watts
90G 270 Watts
125G 375 Watts
180G 540 Watts
225G 675 Watts
300G 900 Watts


What is the Best Aquarium Heater? (Our Recommendation)

So we have discussed quite a lot at this point. It's time to bring in the verdict. The answer may surprise you.

As we mentioned, the best bang for the buck for those who are only able to purchase a single heater would be the Aquaeon Pro Adjustable Heaters. For those of you not on a tight budget though, let's talk about the best setup --- which is setting up an aquarium heater system.

An Aquarium Heater System - Our Recommended Approach

Aquarium heaters unfortunately are prone to a number of failures. These failure points are:

  • The aquarium heater explodes
  • The aquarium heater cracks
  • The aquarium heater's internal thermometer fails
  • The aquarium heater's off/on mechanism fails
  • The aquarium heater's settings reset after a power outage

That is A LOT of failure points. It's also a bit scary to know that the #1 tank crash reason are aquarium heater failures. It's not disease, it's not a power outage, but your heater failing. That's correct, a measly $30 heater can be the cause of you losing hundreds of dollars of fish and pets that you have owned and cherished for many years. 

This is why we recommend purchasing an aquarium heater system. This would encompass:

  • A quality aquarium heater that has a manual adjustable dial
  • Running two heaters instead of one that get us to the recommended wattage level
  • A separate aquarium controller that is accurate at least to 1 degree Fahrenheit and can run both heating and cooling equipment
  • A reasonable piece of cooling equipment that won't break the bank

Eheim Jager and Cobalt Aquatics Neo Therm - Our Recommended Heaters

When it comes to selecting a quality aquarium heater, I feel that the Eheim Jager and Cobalt Aquatics Neo Therm are the two best heaters to select from the lot. The reasoning is:

  • Both the Eheim and Cobalt Neothem are accurate up to 0.5 degrees Fahrenheit 
  • The Cobalt works great in smaller systems, where an Eheim would be considered too bulky to work
  • Both have manual adjustable dials that will not reset during a power outage
  • For larger aquariums with larger fish, I am assuming that the aquarist has a sump or background that allows one to safety store a heater keeping it away from accidents

Both these heaters met my strict criteria and receive my fully recommendation.

Aquarium Heater Failsafe #1 - Running Two Heaters Instead of One

Why would we run two heaters? Well, as I mentioned, heaters have many fail points and one of them is the off mechanism failing. This will mean that the heater will stay on and effectively cook your tank. This is the #1 reason for a heater fail. When you purchase two smaller heaters, if one fails at the on position it is not powerful enough to cook your tank inhabitants. It will stay on and you should have ample warning to notice the failure and act accordingly.

Aquarium Heater Failsafe #2 - Running a Separate Aquarium Controller

Since running two heaters will give you time to act in the event one fails at the on position, you could be out of town or not present for some time to act. This is where a separate aquarium controller comes in. A separate aquarium controller has it's own temperature probe and mechanics separate from an aquarium heater. This provides you with an additional fail safe. Now both heaters AND the controller would need to fail at the same time in order for your tank to experience a crash. That is very unlikely to happen.

The Best Aquarium Heater Controllers

So now let's talk about aquarium heater controllers. The controllers from Finnex and Hyggar are pretty good, but the Finnex controller is only accurate up to 2 degrees and the Hyggar controllers are new to the market. There are two heater controllers that have been around for a while and trusted in other industries aside from the Aquatic industry - namely refrigeration, aquaponics, and beer brewing.

The Inkbird Aquarium Heater Controller - The Best Bang for Buck Controller on the Market

Inkbird Aquarium Heater Controller

I know there will be some folks on the comment section may post and say that I should talk about aquarium controllers, but to me that is a completely separate subject. Aquarium controllers are very expensive and even an entry level controller is going to cost over $200, which is going to be out of the range of many readers of this post.

The inbird is a great budget controller. The Inkbird ITC-308 is a great aquarium heater controller that is accurate up to 1 degree Farenheit. It is easy to program and has the ability to not only control heaters, but cooling equipment as well. This actually provides a TRIPLE FAILSAFE as the cooling function will kick off in the event the aquarium gets too warm. If the aquarium gets too hot or cold, the Inkbird can sound an aquarium letting you know something is wrong. There is also a wi-fi version available so you can get temperature alerts on your phone if the tank gets too warn or too cold!

Bayite Temperature Controllers - A Premium Aquarium Temperature Controller

Baylite Temperature Controller

The Bayite Temperature Controller is a step up from the Inkbird. It has all the same features of the Inkbird, but it is more accurate. With a rated accuracy up to 0.5 degrees Fahrenheit, this controller provides even better assurance that your temperatures stay stable. I typically go with an inkbird on smaller budget builds, but if I have more budget and my client isn't looking to get a controller, this is a definite consideration for me. 

The Best Aquarium Cooling Fan - The Final Fail Safe

Aquarium Cooling Fan

Since these aquarium heater controllers have the ability to cool down a tank, let's get a reasonable piece of cooling equipment. An aquarium chiller is going to be out of the budget range of many aquarists so a cooling fan is a good option for us to look into.

The IPETTITE Aquarium Cooling Fan is a very reasonable piece of an equipment when teamed with an aquarium heater controller can provide some cooling the event your tank gets too warm. It's not a chiller, but it should get you by for most situations. 

Wrapping It All Up On Best Aquarium Heaters

Well, this was a pretty long post. I hope I was able to provide you with the information you need to make the best informed purchase. As I stated earlier, there is a reason for these aquarium heaters to be on our best of lists as they all have their place depending on your aquarium situation and budget.

If you have any questions, please leave a comment in the comment section. Thanks for reading :).

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