Best Submersible Aquarium Heaters to Keep a Fish Tank Still Warm

Recommendation No. 1
Orlushy Submersible Aquarium Heater 300W-Fish Tahk Heater with Adjust Knob Thermostat 2 Suction Cups Suitable for Marine Reef Fish Tank Sump
  • ★300W aquarium heater is suitable for 50 to 80 gallons aquariums,Length - 11 inch,voltage 110-120V, power cord is 6ft, please choose the right wattage aquarium heater according to our size chart.
  • ★It shows an area to adjust the temperature. It's not exactly accurate but it turns easy and can be adjusted at small intervals.
  • ★Explosion Proof: 2mm thickened quartz glass,can be used in fresh water and salt water aquariums,easy to hide in the tank.
  • ★Precise temperature dial from 68 to 89°F allows for complete control of aquatic climate within a 1-degree difference.
  • ★Adjustable Aquarium Fish Tank Water Heater Sensitive and reliable thermostat maintains uniform temperature. Automatic shut off when the temperature is reached
Recommendation No. 2
FREESEA 50 Watt Aquarium Submersible Betta Heater with Aquarium Submersible Thermometer
  • ★【50 Watt Heater】: This Aquarium heater is suitable for 5 to 15 gallons aquariums, Length - 6.8 inch,voltage 110-120V, power cord is 4.0 ft, please choose the right wattage aquarium heater according to our size chart.
  • ★【Temperature range】: 63°F~95°F , It is very easy to adjust the temperature you need, we also deliberately give each customer a free diving thermometer, you can observe the water temperature of the fish tank at any time.
  • ★【Intelligent temperature control】:Automatic constant temperature function, when water temperature reaches to specified temperature value, heater will automatically stop heating, when water temperature is lower than the set temperature, heater will automatically start heating. Furthermore, Automatic safety shut-off feature, and overheating protection.
  • ★【Note】: 1. Aquarium heater is 100% submersible use only, during its heating time, heater must be 100% submerged into the water.,Please unplug the power supply when cleaning the fish tank or aquarium water changes. 2. Heater rod is suitable for people over 16 years of age. Children or minors should be under adult guidance or supervision.
  • ★【SATISFACTION GUARANTEED】Gain the confidence to go hard with us! Our Aquarium Heater is built with durability in mind and safety for every design, In the remote possibility that you’re not satisfied with our product, just contact us, and we will gladly give you a new Aquarium Heater replacement. 12 Month Warranty and 24 Hour Professional After-sales Service.
Recommendation No. 3
Fluval M50 Submersible Glass Aquarium Heater (50 watts)
  • Built in reflective technology mirrors the surrounding colors, making the heater blend into your aquarium environment
  • Shock resistant Borosilicate glass; High density ceramic heat sick
  • Slim profile tube for easy placement; Easy to install
  • Exceptional performance and unsurpassed reliability
  • Suitable for aquariums up to 15 gallons; 50 watts; 3 year warranty

A submersible aquarium heater is a heater you put inside a saltwater or freshwater aquarium to regulate the water’s temperature. Without a heater, fish can struggle to thrive and may even die in water that is too hot or cold.

A submersible heater features a titanium rod and heating elements which sit immersed in the water for the entirety of its life. They provide accurate temperature readings and ensure the water remains at a safe level for the health of your fish.

The market is full of options, but it can take some sifting through them to work out which ones will tick all the boxes for your breed of fish. Take a look at these and see if any stand out.

1. FREESEA Submersible Aquarium Fish Tank Heater

If you want your fish to survive and thrive, then make sure you take a closer look at this submersible aquarium heater from FREESEA. While there are plenty of standout heaters on the market to make sure your fish are comfortable, very few are as advanced and as affordable as this one.

Firstly, you can choose from a 200 or 300-watt option – both of which are bound to suit your tank size of choice. It then has an LED temperature display to show up the accurate temperature of the water. However, the sticking point of this is that there is no Fahrenheit display – only Celsius. This might not appeal to all people. In saying that, its range is still 59 to 93 degrees-Fahrenheit, so it will still be suitable for most freshwater and saltwater setups regardless.

If you happen to turn off the submersible aquarium heater – be it for cleaning or another reason, it’s also going to remember what you set it at once you turn it back on. This is all thanks to the memory function this heater has to offer. Benefit from a precise temperature, compatibility with a broad range of tanks, and an affordable price tag. If you are struggling to find the perfect heater appliance for your aquarium, it won’t hurt to look at this one from FREESEA.


  • 200 and 300-watt options
  • LED temperature display
  • Intelligent thermostat technology
  • 59 to 93 degrees-Fahrenheit temperature range
  • Freshwater and saltwater compatibility
  • Power-off memory function


  • It remembers your temperature preference from when you turn it off to on
  • Affordable price tag
  • Displays your temperature clearly
  • Straightforward to set up
  • The temperature is effortless to maintain
  • Ideal for many different tank sizes


  • It only shows the temperature in Celsius, not Fahrenheit

2. ViaAqua Submersible Heater

Even though this submersible aquarium heater from ViaAqua is more fragile than other units on the market, meaning you need to be more careful, you are still going to love how accurate and useful it is for regulating your aquarium’s water temperature. There’s no denying you are going to have to be more careful, but that doesn’t mean that once it’s safely inside your tank, it won’t operate as effectively as others.

This model of submersible aquarium heater comes with a built-in thermostat and is available in four wattage options – 50, 100, 200, and 300. They all feature quartz glass tubing for extra durability, as well as being fully submersible for an added touch of convenience. What will also have you reaching for the ‘buy now’ button is that they are suitable for both freshwater and saltwater tanks. No matter what fish you have, this submersible aquarium heater can regulate the water temperature well.

To adhere the heater to your tank is effortless as well. It comes with suction cups that sit firmly on your tank to regulate the temperature and make sure it’s consistent throughout. If the time has come to buy an affordable and high-quality submersible aquarium heater, check this one out from ViaAqua.


  • Built-in thermostat
  • 50, 100, 200, and 300-watt options
  • Quartz glass
  • Freshwater and saltwater compatibility
  • Suction cup installation
  • Fully submersible


  • Plenty of wattage options to suit
  • Extra-thick quartz glass
  • Easy installation with suction cups
  • Ideal for saltwater and freshwater tanks
  • Affordable price tag
  • You can use it in a range of tanks
  • Comes with double insulation
  • Safe to use


  • It doesn’t have a protective rubber end to stop you from dropping and damaging it
  • You have to calibrate it to your tank, so it’s accurate
  • More fragile than other submersible aquarium heaters on the market

3. Hygger Submersible Fish Tank Heater

Maintaining water temperature in your aquarium is crucial, but without the best submersible aquarium heater money can buy, it’s a losing game. Don’t let your fish die because you chose the wrong heater. You may find this one from Hygger is all you need to take care of your fish now and into the future.

With a service life of three years or more, it’s already ahead of the competition. Many other heaters on the market do not last longer than a year. You can also choose whether you want with 50, 100, or 300 watts to suit your specific setup.

Everything about this submersible aquarium heater is going to impress. It has an adjustable betta heater, an external temperature controller, and nine heater options too. You can rotate the dial, select your preferred heat, then leave it to work. You may also like to check the built-in thermometer from time to time to see if it’s still working well, as some people notice that it can fail to maintain temperature over time.

This submersible aquarium heater also has a conveniently long power cord, so you don’t always need to be near power, as well as being waterproof and explosion-proof. It’s more expensive than other models, but given its extensive feature list, it’s worth its weight in gold.


  • Adjustable betta heater
  • External temperature controller
  • 50, 100, and 300-watt options
  • 5.4-foot power cord
  • Automatic shut-off safety function
  • Heat-resistant milky quartz tubing
  • Explosion-proof
  • Three-plus year service life
  • Waterproof
  • Nine heater options
  • Built-in thermometer


  • Long service life in comparison to other models
  • It has plenty of safety features
  • The range of wattage options
  • Robust tubing
  • It won’t explode
  • Entirely waterproof
  • Plenty of heating options
  • Long power cord for convenience


  • Not easy to maintain a temperature sometimes
  • Overheats quickly with no water

4. MWGears Submersible Aquarium Heater

Maintaining the water temperature in your fish tank is crucial, and if you don’t have a submersible aquarium heater, there’s a genuine risk your saltwater or freshwater fish could perish. Don’t take the chance. Instead, invest in an MWGears submersible aquarium heater that ensures your water temperature is correct for your fish to thrive.

You can choose a heater that’s either 300 or 500 watts, and enjoy all the safety features that come along with it. While it’s more expensive than other heaters on the market, you pay for quality. It has double-seal material, titanium stainless steel, and it’s also explosion, shatter, and waterproof too. Sealing the deal is the use of high-strength engineering plastic which adds that final touch.

Make use of the adjustable and intelligent temperature chip control system, as well as the convenient placement of the submersible aquarium heater vertical or horizontal. Everything about this heater is with your convenience in mind, so if you want a heater that will look after your fish and provide accurate heating readings, this one is it.


  • 300 and 500-watt options
  • Titanium stainless steel
  • Double-seal material
  • Explosion-proof
  • Shatterproof
  • Waterproof
  • High-strength engineering plastic
  • Adjustable temperature
  • Intelligent temperature chip control
  • Fully-submersible
  • Vertical and horizontal placement


  • It heats the tank quickly
  • Maintains a temperature well
  • You can place it in the tank vertically or horizontally
  • It caters for larger tanks
  • It’s safe to use
  • It features premium materials


  • You have to replace them after one year of use
  • Poor-quality instructions

5. HITOP Submersible Aquarium Heater

If you have a 60 to a 120-gallon aquarium and you’re in need of a way to regulate the water temperature with a submersible aquarium heater, then you’ve come to the right place. This HITOP heater is an excellent example of a premium heater and will deliver on its promise to regulate your tank heating at all times.

It’s available in a 300-watt option to suit a range of 60-120-gallon tanks and is also effortless to set up and begin using. It’s also only 11 inches long – being more than suitable for smaller tanks with not a lot of space to spare.

Instead of easy-shatter heating tubes which frequently appear in most submersible aquarium heaters, this one bucks the trend. It has a PTC oxide ceramic element which will not shatter, bust, or rust. It’s everything you could want it to be and more. This unit also comes with an additional stick-on thermometer to ensure you get an accurate reading, as well as six suction cups to keep it firmly in place inside your tank. Even though you don’t pay a lot for this submersible aquarium heater, you get premium bang for your buck every time.


  • 300 watts
  • PTC oxide ceramic element
  • 60-120-gallon capacity
  • 11 inches long
  • Titanium oxide heating ceramic
  • Stick-on thermometer included
  • Section cups
  • Two-year warranty


  • Compact size
  • Affordable to buy
  • Tubing that won’t shatter
  • Accurate temperature control
  • Rapid heating
  • Generous warranty period
  • Extra suction cups to keep it securely in place


  • Only one wattage option

6. Cobalt Aquatics Aquarium Heater

A submersible aquarium heater shouldn’t take up a lot of room in your aquarium – as the more it does, the fewer fish you can have. Fortunately, this submersible aquarium heater from Cobalt Aquatics solves an all-too-common problem of a lack of space and has downsized its heater range to a more manageable size.

While the heater is small, it doesn’t mean you get any less of a product. You can buy this submersible aquarium heater in 100, 75, and 50-watt ranges, servicing different size fish tanks. They are also only a third of an inch thick, meaning they take up minimal space while still keeping your water temperature at between 66 and 96 degrees-Fahrenheit.

The casing is shatterproof for your peace of mind, it’s a premium neo-therm product that’s almost indestructible, and it has an LED display so you can see the water temperature at all times. What’s more, this submersible aquarium heater is affordable for all, ideal for saltwater and freshwater, and has a one-touch control system. Even though some people think it loses its accuracy over time, it’s still a standout product in an overcrowded submersible aquarium heater market.


  • 50, 75, and 100-watt options
  • 1/3-inch thick
  • Shatterproof
  • European-made
  • Three-year warranty
  • Neo-therm
  • One-touch control system
  • LED display
  • 66 to 96 degree-Fahrenheit range
  • Shatterproof casing


  • Regulates the temperature well
  • Lovely style
  • Affordable to buy
  • Premium materials
  • It won’t shatter
  • You can set the temperature with one button
  • It’s safe and reliable
  • You can use it in saltwater and freshwater


  • The temperature reading can be inaccurate

7. FREESEA Aquarium Fish Tank Heater

The next time you’re on the hunt for a new submersible aquarium heater, don’t look past this one from FREESEA. Don’t let the low-end price tag fool you into thinking it’s an inferior quality product – because it’s anything but.

Firstly, the variety is exceptional. It doesn’t matter what size tank you have; there is a submersible aquarium heater to suit. You can buy them in 300, 200, 100, 75, and 50-watt options. Each submersible aquarium heater also has a temperature range of between 59 and 94 degrees-Fahrenheit. However, it displays the temperature in Celsius only which can be a sticking point for some people.

If the temperature display doesn’t put you off, then you will enjoy other features on offer. You can immerse the heating rods entirely in water, benefit from the red LED display that looks stylish and cool, and the touch buttons as well. It’s also effortless to adjust the temperature, and you get peace of mind from a one-year warranty. This affordable submersible aquarium heater is going to make your aquarium setup complete!


  • 50, 75, 100, 200, and 300-watt options
  • 59 to 94 degrees-Fahrenheit range
  • Touch buttons
  • Cyclic adjustable temperatures
  • Fully immersible heating rods
  • One-year warranty
  • LED display


  • Affordable to buy
  • Plenty of wattage options
  • Straightforward to set up
  • Suitable for many tanks
  • Provides a regular temperature
  • Compact size
  • Safe to use


  • Fish can get stuck in the coils
  • The red LED shows up brightly at night
  • It stays in Celsius instead of Fahrenheit too

8. SZELAM Submersible Aquarium Heater

If you don’t want to spend the earth on a submersible aquarium heater, because your setup already cost a fortune, then you might like to consider this heater from SZELAM. Even though it’s not from the most well-known heater supplier, this heater is an exceptional example of value for money. You pay very little to buy and operate it, but you get continued reliability in return.

When you buy this submersible aquarium heater, you get to choose from a 50, 100, or 300-watt option. Each will be suitable for a different volume of water. It features a protective sleeve to stop electrocution and damage to your fish or aquarium, as well as impermeable sealed technology to reiterate that trust in the submersible aquarium heater. It won’t shatter, rust, and features 1.55mm-thick quartz glass.

When it comes to maintaining a regular temperature, this submersible aquarium heater tries its hardest. It adheres to the wall of your tank with suction cup clamps and offers a temperature range between 68 and 94 degrees-Fahrenheit. It also shows the temperature on a digital gauge. For the most part, it’s an accurate reading, but some customers have had trouble.

Rather than spend a fortune to regulate your water temperature, pay less and get ultimate bang for your buck with SZELAM.


  • 50, 100, and 300-watt options
  • Protective sleeve
  • 1.5mm-thick quartz glass
  • Shatter-resistant
  • Impermeable sealed technology
  • Suction cup clamps
  • 68-94 degrees-Fahrenheit range
  • Digital temperature gauge


  • Affordable price tag
  • Plenty of options to suit different tank sizes
  • You can use it with fresh or saltwater fish tanks
  • The thermometer is accurate
  • Maintains a regular temperature
  • Effortless to set up
  • The sleeve stops shocks and makes sure your fish are safe


  • The suction cups are not reliable
  • the thermometer can be inaccurate for some people

9. Hygger Titanium Aquarium Heater

Even though you may not like to buy a submersible aquarium heater from a no-name brand, you will change your mind once you give this one from Hygger a chance. Of course, it’s not a leading brand yet, but once more people find out about what it can offer, it won’t be long until it becomes one.

This submersible aquarium heater has many standout features that will see you buying more than one for your aquarium setup. It has titanium tubing that won’t rust or shatter, comes in 200, 100, or 50-watt options, and you can use it in a tank with between 20 and 45 gallons of water.

When it comes to heating your tank correctly, this submersible aquarium heater delivers. It has a generous heating range of between 32 and 104 degrees-Fahrenheit but can display the temperature on the LCD screen in Celsius or Fahrenheit depending on your preference. It’s also ideal for many tanks and will distribute heat effectively as long as you secure it with its two suction cups near a flow of water. With an affordable price tag to seal the deal, there’s every reason to consider purchasing this submersible aquarium heater from Hygger.


  • Titanium tubing
  • 50, 100, or 200-watt options
  • Two suction cups
  • Easy-mount system
  • Low to high controller
  • Shatterproof
  • Anti-corrosion
  • Dual LCD
  • 32 to 104-degree heating range
  • Automatic shut-off system
  • 20-45-gallon tank capacity


  • You can view the temperature in Celsius or Fahrenheit
  • It has a broad temperature range
  • Affordable price tag
  • Secures in place firmly
  • It won’t shatter or rust
  • Suitable for many tank types
  • Accurate thermometers


  • You have to run it near a high flow for even heat distribution

Considerations for Purchasing a Submersible Aquarium Heater

If you have an aquarium with freshwater or saltwater fish, you will learn soon enough the implications of not having a submersible aquarium heater – or having an inferior quality one. Without proper water temperature regulation, your fish can fail to thrive – and can even die. You can’t pick the cheapest model with the least features and hope for the best. Instead, you need to think about what your fish require and whether the heater you have picked is up to the task. Here is how to work it out.

  1. WattageThe wattage of your submersible aquarium heater of choice matters a lot. The lower the wattage, the smaller space it can heat. Before you jump online and begin looking for a new heater, make sure you know how many gallons your aquarium is. Most heater suppliers will tell you the size aquarium their heaters will suit. The higher the wattage, the warmer the water.
  2. Heat rangeSome fish require a particular water temperature to survive, so you need to read all the fine print of each submersible aquarium heater to make sure the one you choose is the one to tick all the boxes for their needs. Most sit between 50 and 90 degrees-Fahrenheit.
  3. DisplayMost people in the United States are familiar with temperatures in Fahrenheit as opposed to Celsius. However, some submersible aquarium heaters on the market only display the temperature in Celsius. While it’s not the end of the world if you have to convert it to Fahrenheit in your head, it’s going to be more convenient if you choose a heater that suits what you prefer to begin with. Most also have LED or LCD screens.
  4. LongevityYou could spend hundreds of dollars on a new submersible aquarium heater, but the reality is, they don’t last forever. Lower-end models can fail long before the year is up, while even the more expensive ones can provide faithful service for around three years. Because they spend their entire life in water, they are continually working hard to keep it warm and protect the fish from electrocution.

    Working so hard means they burn out. Read the fine print and choose a submersible aquarium heater that lasts the longest time – even if you have to pay a little more for this guarantee and a warranty. It can save you a lot of hassle in the long-term.

Last update on 2020-07-27 / Affiliate links / Images from Amazon Product Advertising API

Leave a Comment

Your email address will not be published. Required fields are marked *