Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

10 Best Aquarium Heaters – 2023 Reviews & Top Picks

Lindsey Stanton Profile Picture

By Lindsey Stanton

An aquarium heaterBoth aquarium fish and plants need the right temperature to stay alive and healthy. This is especially true when it comes to tropical fish and tropical plants. Without the right temperature, they will not stay alive very long.

However, there are a lot of different aquarium heaters out there, so we are here to help you find the best fish tank heater out there. Whether you need a 10-gallon aquarium heater or any other size, we aim to help you find the right one for your tank.


Quick Comparison of Our Favorite Picks in 2023

Rating Image Product Details
Best Overall
Eheim Jager Aquarium Thermostat Heater Eheim Jager Aquarium Thermostat Heater
  • Fully submursible
  • Automatic shutoff when water too low
  • Made of shock resistant shatterproof glass
  • Premium Choice
    Second place
    Aqueon Pro Adjustable Heater Aqueon Pro Adjustable Heater
  • Electronic Thermostat accurate to +/- 1°
  • Limited Lifetime warranty
  • Shatterproof and nearly indestructible
  • Third place
    Tetra HT Submersible Aquarium Heater Tetra HT Submersible Aquarium Heater
  • Good for small tanks
  • Fully submersible with run dry protection
  • No adjustment required
  • Hydor In-Line External Heater Hydor In-Line External Heater
  • Suitable for marine and tropical aquariums
  • Easy to use
  • Great for larger tanks
  • Fluval Advanced Electronic Heater Fluval Advanced Electronic Heater
  • LCD temperature display
  • Safety shut-off and integrated fish guard
  • Range of 68 to 93 degrees Fahrenheit
  • Benefits Of Using A Heater In Your Aquarium

    Most fish require the proper temperature to keep them in prime condition. Without the right temperature, most fish will die sooner than later.

    The same goes for many tropical aquarium plants which also require the water temperature to be quite high. Having the right water temperature will also help make the water easier to filter and maintain too, but this benefit is very minimal and really does not matter all that much in the long run.

    The 10 Best Aquarium Heaters

    Here we have a selection of 10 aquarium heaters that we feel are worth a mention, each of which comes with quite a few benefits and maybe a couple of drawbacks too. These aquarium heater reviews should help you narrow down your decision on finding the right option.

    1. Eheim Jager Aquarium Thermostat Heater

    Eheim Jager Aquarium Thermostat Heater

    Check Price on Chewy

    The Eheim Jager is a fully submersible heater that comes in a range of power levels. This particular aquarium heater comes in a 25, 50, 75, 125, 150, 200, 250, and 300-watt option, making it a good choice for pretty much every size of aquarium out there.

    It is fully submersible, plus it comes with a run-dry protection feature so it stops running in case it is no longer submerged. It comes with a nearly 6-foot long cord, which is also nice in terms of setting it up.

    The suction cups that come included also help make installation easy. This thing is made out of shatterproof and shock-resistant glass, which helps to make it quite durable, plus it makes it safe for your fish too.

    This Eheim Heater can be adjusted from 18 to 34 degrees (65 to 93 Fahrenheit) to suit the needs of your aquarium. It also features a TruTemp dial for accurate heater calibration. The on/off indicator light tells you when it is running and when it is off. This item can be used for both salt and freshwater tanks.

    All in all, we think this is the best aquarium heater this year.

    • Comes in many wattage options
    • Ideal for many sizes of aquariums
    • Quite durable
    • High level of safety
    • Has a calibration dial
    • Wide adjustable temperature range
    • Easy to mount

    • Calibration is not very easy
    • Temperature accuracy is questionable

    2. Aqueon Pro Adjustable Heater

    Aqueon Pro Adjustable Heater

    This particular aquarium heater comes in a few different wattage options including 50, 100, 150, 200, and 250 watts. It should be fine for most aquariums except for the very largest ones. These heaters are built with a very durable and solid outer shell, one that is shatterproof as well as shock-resistant, making them safe for fish and quite durable too.

    This heater can be used for both freshwater and saltwater tanks, which is convenient. In terms of setting it up, it can be positioned vertically or horizontally depending on your needs. However, it does not seem to come with any mounting brackets, which is a bit of an issue.

    This is a fully submersible heater, so you can pop it right in the tank. To prevent it from overheating and running dry, it will automatically shut off when it is not fully submerged.

    The Aqueon Pro is fully adjustable from 68 to 88 degrees, which is a decent temperature range, plus it should be accurate to within roughly 1 degree. The included LED light will let you know when this heater is running and when it is not.

    • Fully submersible
    • Run dry protection
    • Fairly accurate
    • Easy to adjust
    • Decent temperature range
    • Decent level of durability
    • Fresh and saltwater use
    • Can be mounted vertically or horizontally

    • Does not come with mounting gear
    • Seems to have problems with shocking fish on occasion

    3. Tetra HT Submersible Aquarium Heater

    Tetra HT Submersible Aquarium Heater

    This is yet another good fully submersible aquarium heater to go with. It’s a fairly convenient option as it does come with the included mounting hardware, suction cups which you can just plaster onto the interior of the tank.

    This thing can be positioned vertically or horizontally for your convenience. Seeing as it is fully submersible, it comes with a run-dry protection system so it does not overheat in case it is not fully submerged. Its small size makes it ideal for tanks where real estate is limited as it can be easily hidden behind plants or something else of the sort.

    This model comes in a 50 or 100-watt option, so it is only good for smaller tanks between 2 and 10 gallons, ones that also have canopies or hoods, as the power level here is limited. The Tetra Aquarium Heater is designed to keep the water temperature steady at 78 degrees.

    So, it is a good option if you need your tank to be at 78 degrees all the time, but it cannot be adjusted, which might be a problem for some people. While it does work pretty well, the accuracy it provides in terms of maintaining a constant temperature is somewhat questionable. Its durability is also a little questionable.

    • Good for small tanks
    • Ideal for tanks that need to be at 78 degrees
    • Fully submersible with run-dry protection
    • Small and easy to conceal
    • Easy to mount – vertical or horizontal

    • Cannot be adjusted
    • Limited durability
    • Limited power levels

    4. Hydor In-Line External Heater

    Hydor In-Line External Heater

    This is the first-in-line heater on our list today, a pretty decent one at that. It might not look special, but we do like how it is totally external, as it does not take up any space within an aquarium, thus saving prime real estate for fish and plants.

    This is not a submersible heater, nor can it be submerged. Funny enough, while water does flow through it to be heated up, the exterior is not too tough and susceptible to water damage, so try not to get it wet. If it is not clear, this thing is meant to be attached to the return line from an external filtration unit.

    The Hydor In-Line heater comes in a 200 and 300-watt option. Therefore, it is really only ideal for larger tanks and is too powerful for smaller aquariums. This option is said to be highly adjustable with a wide temperature range, but what this range is, is somewhat unclear, as well, it does not seem to be the most accurate option around.

    The Hydor does come with special overheating protection so it never gets too hot and causes any electrical or fire risks outside of the aquarium.

    • Space saver
    • Easy to mount on a return line
    • Great for larger tanks
    • Wide range of temperature
    • Overheat protection
    • Easy to conceal

    • Susceptible to water damage
    • Cannot be used for smaller tanks
    • Not 100% accurate

    5. Fluval Advanced Electronic Heater

    Fluval Advanced Electronic Heater

    This is another cool fully submersible aquarium heater to consider, one that comes with easy mounting brackets for a quick setup. It can also be mounted horizontally or vertically, which is convenient. Like the other submersible options here today, this one also comes with a special kind of overheat protection so it does not run dry and get too hot.

    Now, what is neat about this option is that it comes with dual temperature sensors and an LCD which tells you the temperature of the aquarium at all times. It’s a nice digital aquarium heater to keep in mind.

    To increase safety for fish, this thing comes with an advanced fish guard to keep your pets away from the heating elements. To be clear, you can get the Fluval Heater in 50, 100, 200, and 300-watt power options, making it quite versatile and suitable for several tank sizes.

    It can be fully adjusted in increments of 0.5 degrees, making it quite precise, with a fairly wide temperature range of 68 to 93 degrees. The slim profile of this thing does help save a bit of space inside any aquarium.

    • Comes with an accurate thermostat
    • Wide temperature range
    • Easy and accurate adjustments
    • Factory calibrated
    • Good for big and small tanks
    • Various safety features
    • Does not take up too much space

    • Limited durability
    • The accuracy of the thermostat is a little questionable
    • Should not be used for saltwater

    6. JBJ True Temp Titanium Heating System Kit

    JBJ True Temp Titanium Heating System Kit

    Yet another nice submersible aquarium heater to go with, this one is ideal for large and even larger tanks. In terms of the wattages, it comes in a 150, 300, 500, 800, and 1000 watt option. In other words, this thing is powerful, very powerful, and it can be used for some really big tanks.

    However, although it is small and does save space, it should not be used for small tanks. It comes with all of the mounting hardware included and can be mounted vertically or horizontally depending on your needs. While the guard is not the most durable out there, it will offer your fish some protection from the heating element.

    What is cool here is that the JBJ comes with a remote temperature sensor and control unit, more or less a remote control so you can control it without getting your hands wet. It does have a fairly wide temperature range, plus it works pretty fast too, not to mention that it should be accurate to within about 0.5 degrees Fahrenheit.

    Although, with that being said, heaters like this are very rarely as accurate as advertised. Keep in mind that this unit needs to be fully submerged, but it does not really feature good overheat protection.

    • Durable heating unit.
    • Fairly accurate.
    • Easy to adjust.
    • Comes with a remote temperature sensor and control unit.
    • Fully submersible.
    • Comes with mounting hardware – vertical or horizontal.
    • Comes with a guard.

    • The durability of the guard is limited.
    • Only good for big tanks.
    • Does not have good overheat protection.

    7. Finnex Hang-On Digital Controller Aquarium Heater

    Finnex Hang-On Digital Controller Aquarium Heater

    This is the first immersible aquarium heater here today. Now, we do like how it hangs on the back of the tank and comes with all mounting hardware. It is therefore quite easy to set up and it does not take up much room in the tank either.

    Keep in mind that the motor here is sensitive and that this unit cannot be fully submerged or else it will break down and most likely shock your fish too. Other than that, this is a pretty decent choice to go with. Although the top half is sensitive to water damage, as far as immersible heaters go, this thing has a decent level of durability.

    This unit comes in 50, 100, 150, 200, 250, and 300-watt power options, making it ideal for smaller and larger tanks alike. It has a pretty wide temperature range and is accurate to about 2 degrees Fahrenheit, which is not too bad. The digital LCD control system it comes with is fairly easy to use.

    It even has a memory chip to restore the previous settings used. The Finnex does work very fast, as the heating element is designed to be fast-acting. One thing to note here is that it does not come with any kind of guard to protect the fish.

    • Easy to mount.
    • Space saver.
    • Fast heating.
    • Various power options.
    • Good for smaller and larger tanks.
    • Decent level of accuracy.
    • Easy to control LCD remote.
    • Memory chip included.

    • No guard for fish.
    • The temperature sensor is iffy – acts funny at times.
    • The plastic remote is not durable at all.

    8. Aquatop Quartz Glass Submersible Heater

    Aquatop Quartz Glass Submersible Heater

    This is a nice little heater to go with, a small 50-watt heater that is ideal for tanks up to 13 gallons. It does have limited power, so it will not be able to handle any kind of larger tank at all. However, for smaller tanks, especially ones with hoods or canopies, it should work just fine.

    This particular unit can be easily adjusted from 68 to 93 degrees Fahrenheit, so it does have quite a wide temperature range, yet it is not always 100% accurate in terms of maintaining a steady water temperature. We do like how this unit can be used for both freshwater and saltwater tanks alike.

    The Aquatop is a fully submersible heater, so water will not damage it. The quartz case is fairly durable, shatterproof, and should never allow your fish to be shocked. This thing does feature overheat protection in case it is not 100% submerged.

    This unit is also fairly easy to install, as it comes with suction cups, as well, it can be mounted vertically or horizontally for your convenience. Although it does need to be fully submerged, it is fairly small, so it will not take up too much space within your aquarium.

    • Good for small tanks.
    • Fairly durable.
    • Easy to install.
    • Easy to adjust.
    • Wide temperature range.
    • Small space saver.
    • For fresh and saltwater use.

    • The heating element does not last too long.
    • Manages to get rusty over time.
    • Not the most accurate.

    9. Uniclife Submersible Aquarium Heater

    Uniclife Submersible Aquarium Heater

    This is a small but effective submersible heater for small fish tanks. It comes in a 25 and 50-watt option, which makes it ideal for very small tanks, but nothing over 15 gallons. This particular unit can be adjusted from 61 to 90 degrees Fahrenheit, which is a pretty wide temperature range, making this unit ideal for most tropical fish tanks.

    Although the accuracy which this unit comes with is a bit questionable. It also comes with an easy-to-use thermometer, a separate one, so you can always keep track of the water temperature.

    The Uniclife Heater is fully submersible, so you really do not have to worry about durability. It features a solid glass housing that is shatterproof and will not let out electrical currents, thus keeping your fish safe.

    This thing is very easy to mount as it comes with the required suction cups included, plus it can be mounted both vertically and horizontally depending on what you need. Although it will take up a bit of space in the tank, it is not too large, so it’s not the worst ever.

    • Wide temperature range.
    • Easy to mount.
    • Easy to control.
    • Comes with a separate thermometer.
    • Durable and safe glass housing.
    • Does not take up too much space.

    • Only ideal for very small tanks.
    • Not particularly accurate.

    10. Freesea FS-28 Small Aquarium Heater

    Freesea FS-28 Small Aquarium Heater

    This is definitely a unique little aquarium heater to go with, one that comes in a 75 watt and 100-watt option. It is ideal for smaller fish tanks, but really nothing over 20 or 25 gallons, as it does have limited power.

    What is neat is that this thing comes with a memory function so it always remembers the last setting after being turned off. It does have a slim build, so it does not take up too much space within a tank.

    This heater has a fairly wide temperature range and is easy to adjust, plus it will shut off when the ideal temperature is attained, and will then work to maintain a steady water temperature. Yet, how accurate this heater is, is a little questionable.

    At the same time, this thing does need to be fully submerged, plus it does not seem to be all that durable either. The guard features large gaps in between, so this thing cannot be used for tanks with small fish as they might get burned by the heating elements.

    • Space saver.
    • Good for small tanks.
    • Easy to mount.
    • Easy to adjust.
    • Memory function.

    • Cannot be used for small fish.
    • Not ideal for large tanks.
    • Questionable durability.

    Buyer’s Guide: How to Choose the Best Aquarium Heater

    Types Of Aquarium Heaters

    There are 5 main types of aquarium heaters that you can go with, each of which works to the same end, but has slightly different features.

    Immersible Heater

    An immersible heater hangs on the side of the aquarium. It features a heating unit in the main body which hangs down into the tank. They feature a display at the top for temperature adjustments.

    While they are quite common, the part which sticks out of the water tends to suffer from heat damage and sometimes water damage too. Due to being located at the surface of the tank, they don’t do great for even heat distribution. These are best used for fairly small fish tanks.


    Fully submersible aquarium heaters are perhaps the most popular choice to go with. These can be fully submerged in an aquarium, and in fact, they have to be fully submerged while in use or else they will break. These usually have a really solid glass housing to ensure that the heating elements are not directly exposed to the water.

    These things come in many sizes and power levels, plus they tend to be very easy to mount as well, making them one of the most popular types of aquarium heaters out there.

    fish in aquarium with heater
    Image Credit: Maryna Kravtsova, Shutterstock


    This kind of heater is a popular choice to go with if you have an external filter, such as an external canister filter. This type of heater connects to the outgoing water tube from the filter, therefore heating the water as it re-enters the tank, after already passing through the filter.

    While not too many people go with this option, due to also needing a canister filter, they do work quite well, are usually fairly accurate, and can be quite useful too. They are not the number one choice due to mounting and installation difficulties, but they do work.


    In filter heaters are honestly not all that popular, nor are they very effective or useful. Sure they heat water in your aquarium just like other heaters, but in all reality, they are a bit of a pain in the butt.

    Either you have to get a filter that already has a heater built into it, or you have to buy a separate heater and filter, both of which are compatible with each other. The big bonus here is that they are good in terms of saving space, but maintenance and making adjustments are not all that fun.


    In the sump, heaters are the other option to go with, one that is alright, but usually not the best choice. These things need to be placed inside of a sump, which is OK if you have a sump. However, many people with basic aquariums just do not have, need, or want sumps.

    Therefore, if you do not have a sump, this is not a good option for you. Although, if you have a sump, this does make for a good option because it puts some distance between the heater and your fish, thus adding some extra safety to the equation.

    divider fish plants 2

    Aquarium Heater FAQs

    There are a few important questions about aquarium heaters that you probably want answered, so let’s go over some of the most pressing ones right now.

    Can Aquarium Heaters Be Fully Submerged?

    Well, some can and some cannot. As we have discussed above, there are submersible aquarium heaters which not only can be fully submerged but actually need to be fully submerged to work and stay whole.

    As you can see from the above reviews, most of the best options to consider are of the submersible variety. However, there are also immersible aquarium heaters, as well as ones that never touch the inside of your tank at all.

    How Long Do Aquarium Heaters Last?

    This is a bit of a tricky question, as it really depends on the size, quality, brand, and yes, the price you pay for it. There is no denying the fact that you get what you pay for, so the less you pay, the less time it will take for the thing to break down.

    Generally speaking, you can probably expect a normally priced aquarium heater to last about 1.5 to 2 years, with higher-end models being able to go for maybe 3 years. However, there are some which are known to only last for 6 or 8 months.

    What Temperature Should A Freshwater Aquarium Be?

    This is a very hard question to answer as well, as it does not depend on the type of water, such as freshwater or saltwater, but one type of fish in the tropical aquarium. Generally speaking, a tropical fish tank will need to be kept between 72 and 82 degrees Fahrenheit.

    However, as we said, it all depends on the type of fish and plants that are housed within the tank. It’s also worth looking into a good heater controller, we have reviewed our favorite 5 here.

    aquarium filter nozzle with bubbles
    Image Credit: Lapis2380, Shutterstock

    Can You Put A Heater In A Plastic Fish Tank?

    While you can put a heater in a plastic fish tank, or acrylic, in other words, it might not be the wisest choice. Some aquarium heaters get really hot and they may melt or damage the acrylic, but this is quite unlikely.

    We would recommend going with a glass tank, but as long as you are careful and have a high-quality heater, it should all be just fine.

    How To Heat A Fish Tank Without A Heater?

    There are a few ways you can go about heating your fish tank without a heater. For one, you can leave it somewhere where there is a lot of sunlight and ambient light. You can keep it higher up because heat rises.

    You can also install an aquarium light, as they tend to give off a fair amount of heat. You can also put a canopy or hood on the tank to keep any heat in the water, or at least to stop it from dissipating as fast.

    What’s The Best Heater For A 5 Gallon Fish Tank?

    For a small 5-gallon fish tank, you really do not need a heater that is more powerful than 25 watts or 50 watts at the very most. Anything more than that will be too powerful.

    Using a small submersible or immersible heater is your best bet here. Just don’t get anything big as you don’t have much room to spare in a 5-gallon tank.

    What Size of Heater Do I Need For A 30-gallon Aquarium?

    For a 30 gallon aquarium, a 125 or 150-watt heater should be more than enough. However, anything smaller or larger than that is not going to be ideal.

    We have also covered a post on quiet air pumps that you might find helpful.



    Keep in mind folks, the best aquarium heater for you is the type of heater that works best for your setup and the size which is ideal for the amount of water in your tank. Other than that, just pay attention to some of the key aspects that we have repeatedly talked about above and you will be just fine.

    Related Articles

    Further Reading

    Vet Articles

    Latest Vet Answers

    The latest veterinarians' answers to questions from our database