
Just as it’s important to regularly test your aquarium’s water, maintaining a suitable water temperature for your fish is absolutely necessary. Luckily, there are many great aquarium heating and chilling options on the market today that are safe to use, user-friendly, and affordable. In this guide, we’ll showcase some of the best aquarium heaters you can buy and let you know what makes them great.
Buying Guide for Aquarium Heaters

Why buy an aquarium heater?
Since fish don’t generate their own body heat, they rely on the temperature of the water around them in order to maintain a healthy body temperature. Thus, investing in a reliable aquarium heater can prolong the lives of your fish and ensure they’re comfortable and happy in their aquarium. Aquarium heaters also help keep your aquarium’s water temperature stable. This means that fluctuations in the temperature of your home won’t cause your fish any discomfort in their temperature-regulated environment.
What should you look for in an aquarium heater?
- Tank Size: The size of your tank is very important, as this will largely determine what kinds of aquarium heaters you will be looking for. Naturally, high-wattage options are ideal for larger tanks as they can bring the water temperature to the desired level quicker and help it stay there while minimizing the aquarium heater’s operation time.
- Durability: While no aquarium heater is break-proof, finding one with features such as shatterproof glass and an overall rugged design can prevent you from having to replace it during ordinary use. Additionally, it’s crucial to follow an item’s instructions when installing or removing aquarium heaters since this is when breakage is most likely. Thus, you should also seek out a model that comes with clear instructions.
- Ease of Use: Thankfully, most aquarium heaters are very simple to set up and operate. Seek out a product that can automatically power on and off in order to efficiently maintain your target temperature. Finding a model that makes changing the target water temperature as easy as possible is also a good idea.
What is the difference between hanging and submersible aquarium heaters?
There are several main types of aquarium heaters. Hanging aquarium heaters are well-known as the most inexpensive and common aquarium heating option on the market. They hang from the edge of your tank and heat water via a heating element within a glass tube. While these are typically not suitable for marine or brackish water aquariums, they are budget-friendly options for tropical freshwater fish.
On the other hand, submersible aquarium heaters can be fully submerged in water, making them a more effective heating option than most hanging aquarium heaters. Submersible aquarium heaters also afford you more options for how and where to place the heater and can often be used in freshwater or saltwater aquariums.
Our Picks for the Best Aquarium Heaters
Orlushy Submersible Aquarium Heater
This versatile aquarium heater scores points for its rugged build quality and stable heating.
Pros: Whether you have a tiny aquarium for a single tropical fish or a large, 70-gallon tank, the Orlushy Submersible Aquarium Heater’s sturdy design and reliable temperature dial make it a great choice. This aquarium heater comes equipped with an accurate thermometer and handy indicator light to ensure you know that it’s operating properly. It also stands out for its long power cord, making it easy to set up even if your aquarium isn’t located right next to an AC outlet.
Cons: This aquarium heater’s thermostat is somewhat of an inexact science, so you will need to pay close attention to the aquarium thermometer’s reading and calibrate the heater until your water is at the perfect temperature. Thankfully, after this has been done, the aquarium heater is great at maintaining a stable temperature.
Bottom Line: While this isn’t the most budget-friendly aquarium heater you will find, you will be hard-pressed to find something more reliable or rugged at its price point. It’s an especially good choice for those prone to cracking their aquarium heaters since it can take more use and abuse than similar models. That being said, its inexact thermostat shouldn’t be trusted without a reliable aquarium thermometer, such as the one this product comes with.
Tetra HT Submersible Aquarium Heater
This budget-friendly aquarium heater automatically keeps your water at an ideal temperature for most tropical fish.
Pros: If you have tropical fish, the Tetra HT Submersible Aquarium Heater’s plug-and-play design makes it easy to warm up the water in your aquarium without unwanted guesswork. It keeps temperatures around 78 degrees Fahrenheit and sports a simple, compact design that doesn’t draw attention away from your fish. It’s also fully submersible, meaning it can be situated vertically or horizontally while providing safe, stable heating.
Cons: While this non-adjustable aquarium heater is great for aquariums that house tropical fish, its lack of adjustability makes it much less versatile for aquariums with specialized needs. Also, since the target temperature can’t be tweaked, it would be wise to use an aquarium thermometer with this product so that you can be sure it is operating properly.
Bottom Line: If you’re seeking a low-profile aquarium heater for your tropical fish aquarium, this model is a reliable option that will save you a few dollars in the process. That being said, its lack of an adjustable thermostat will understandably be a deal-breaker to those who desire a more hands-on approach to maintaining their aquarium.
FREESEA Aquarium Heater
This aquarium heater sports a built-in thermostat that makes it easy to maintain your target temperature.
Pros: The FREESEA Aquarium Heater is another reliable option that is available in a convenient array of wattage options suitable for large and small tanks. Featuring an easy-to-adjust thermostat, this aquarium heater provides stable heating by automatically powering on and off to maintain the target temperature. It also sports an indicator light so that you will know whether it is heating the aquarium or resting.
Cons: This aquarium heater might be a bit more fragile than some of the more rugged options on the market. That being the case, it will be important to follow the product’s directions and handle it with care. It’s also worth noting that this product’s power cord is only 4 feet long, so make sure this is an ideal length for your aquarium setup.
Bottom Line: Finding an excellent aquarium heater for small 5-gallon tanks can be tricky, but this option from FREESEA is dependable enough to make it a great option. While this isn’t the most durable aquarium heater on the market, it shouldn’t cause problems as long as it’s appropriately installed with gentle hands.
Eheim Jager Aquarium Thermostat Heater
This durable aquarium heater comes equipped with an easy-to-adjust thermostat and some useful safety features.
Pros: Eheim Jager is a brand that’s nearly synonymous with aquarium heaters, and the Eheim Jager Aquarium Thermostat Heater stays true to the brand’s high standards. Sporting a wide variety of styles to suit nearly any aquarium size, this product stands out for its shatterproof glass construction and easy-to-calibrate thermostat. This heater also features some nice safety features, including Thermo Safety Control, which automatically shuts the heater off when it’s removed from the water.
Cons: Given that this product sports a fairly similar design and features as other, more budget-friendly aquarium heaters, some may be turned away by this product’s price tag.
Bottom Line: While many people will go with an aquarium heater that is half the price of the Eheim Jager Aquarium Thermostat Heater, those who value quality will find a lot to love about this product. Also, its impressive durability makes it a great choice for those who are accident-prone or have broken other aquarium heaters in the past.
Cobalt Aquatics Neo-Therm Pro Aquarium Heater
This next-level aquarium heater stands out thanks to its LED display and highly-accurate thermostat.
Pros: If you’re in the market for a next-level aquarium heater, the Cobalt Aquatics Neo-Therm Pro Aquarium Heater is worth its premium price tag. Featuring an easy-to-read LED display and exceptional build quality, this aquarium heater is just about as shatterproof as they come. It also outperforms competitors in terms of heating accuracy and stability, making it an excellent choice for those who want their fish to enjoy the most luxurious life possible.
Cons: Simply put, this aquarium heater is undoubtedly one of the most impressive models out there in terms of durability and performance. That being said, is it truly worth four to five times as much as the other aquarium heaters on this list? Those who are on a tight budget will justifiably pass on this product, and it’s hard to blame them for that.
Bottom Line: If you’re looking for something thin, accurate, and easy-to-use, you will probably love everything this aquarium heater brings to the table. However, its next-level performance probably isn’t worth the cost for those who are on a tight budget.
Final Thoughts
If you’re leaving your aquarium’s water temperature up to fate, your fish will likely want to have a stern word with you. Thankfully, there are a wide variety of aquarium heaters out there. That being said, make sure that the model you pick is a great choice for both your fish and your aquarium size before settling on the product that’s right for you.