How to Choose the Right Aquarium Heater?

There are a few things to consider when choosing an aquarium heater, such as the size of your tank, the climate you live in, and your budget.

Let’s dig into detail…

Size is probably the most crucial factor when choosing an aquarium heater. You’ll need to know the gallons of your tank so you can purchase a heater that is rated for that size. It is vital to get a heater that is the correct size for your tank because if it’s too small, it won’t be able to heat the water properly, and if it’s too big, it could overheat the water.

The climate you live in will also affect what type of aquarium heater you need. If you live in warmer weather, you won’t need as powerful of a heater as someone who lives in a colder climate.

Your budget is also something to consider when choosing an aquarium heater. Heaters can range in price from around $20 to over $200. It’s crucial to find a heater that fits your budget but also does an excellent job of heating your tank.

Some other things to keep in mind when choosing an aquarium heater are the warranty, the features, and the energy efficiency. Finding a heater with a good warranty is important if it breaks down within the first few years.

The features of the heater are also something to consider. Some heaters come with automatic shut-offs, thermostats, and timers. These features can be beneficial in keeping your tank at the correct temperature.

Finally, you’ll want to consider the energy efficiency of the aquarium heater. Heaters that are more energy efficient will cost more upfront but will save you money in the long run on your electric bill.

Now that you know some things to consider when choosing an aquarium heater, you can start shopping for the perfect one for your tank. There are various types and sizes of heaters available, so you should be able to find one that fits your needs perfectly.

So, what are you waiting for? If you’re looking for a great selection of right aquarium heater? Check out our selection of the 10 best right aquarium heater today!

Top 10 Best Selling Aquarium Heaters

Best Seller #1

Hitop 50W/100W/300W Adjustable Aquarium Heater, Submersible Glass Water Heater for 5 – 70 Gallon Fish Tank (50W for 5-15 Gallon)

Hitop 50W/100W/300W Adjustable Aquarium Heater  Submersible Glass Water Heater for 5 – 70 Gallon Fish Tank (50W for 5-15 Gallon)

  • Explosion Proof: 2mm thickened explosion proof glass, 33% thicker than the normal, safer for both human and animals.
  • Application: 50W water heater is suitable for 5 – 15 gallon tank, also suitable for both saltwater and freshwater.
  • Accurate Temperature: Temperatures from 68°F to 93°F (20°C – 34°C), come with a thermometer sticker, convenient to detect the water temperature without another pay.
  • Long Service Life: Adopt 8-slot multi-branched heating wire ceramic frame, shorter length, 7.8*1*1 in(20*2.5*2.5 cm), better heat dissipation, and can save more space for your fishes.
  • Complete Accessories and Warranty: Except for thermometer, also equipped with 3 suction cups, one for replacement, and offer 12 months warranty, leave you no worries after you buy it.

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Best Seller #2

Orlushy Submersible Aquarium Heater,150W Adjustable Fish Tahk Heater with 2 Suction Cups Free Thermometer Suitable for Marine Saltwater and Freshwater

Orlushy Submersible Aquarium Heater 150W Adjustable Fish Tahk Heater with 2 Suction Cups Free Thermometer Suitable for Marine Saltwater and Freshwater

  • ★150W aquarium heater is suitable for 20 to 30 gallons aquariums,Length – 9.5″,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.

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Best Seller #3

Fluval M50 Submersible Heater, 50-Watt Heater for Aquariums up to 15 Gal., A781

Fluval M50 Submersible Heater  50-Watt Heater for Aquariums up to 15 Gal.  A781

  • Aquarium heater that blends into the aquarium environment with built-in reflective technology that mirrors the surrounding colors
  • Computer-calibrated thermostat and easy-to-adjust temperature control dial
  • Shock resistant Borosilicate glass and high density ceramic heat sick
  • Easy to install with slim profile tube for easy placement
  • 50-watt heater suitable for freshwater and saltwater aquariums up to 15 gallons with a 3-year warranty

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Best Seller #4

HITOP 25W 50W 100W 200W 300W Adjustable Aquarium Heater, Submersible Fish Tank Heater Thermostat with Suction Cup (50W)

HITOP 25W 50W 100W 200W 300W Adjustable Aquarium Heater  Submersible Fish Tank Heater Thermostat with Suction Cup (50W)

  • 🐟HITOP aquarium heater 50W, length 7.2-inch, power cord 4.9ft, designed for small fish tanks, recommended for aquariums up to 15 Gallons.
  • 🐟 Thickened Glass: 2mm thickened quartz glass, 33% thicker than 1.5mm normal aquarium heaters, much safer for human and your lovely fishes, your pets will no longer fear the winter.
  • 🐟Adjustable and easy to use: This aquarium heater, adjustable temperature range 68 ~ 93 °F, after setting the temp you want, will on or shut off automatically when the water temperature changes, no extra adjustment is required.
  • 🐟Accurate Temperature Control: This fish tank heater built-in thermostat, will automatically keep the water at the set temperature within±2°F error. Comes with an sticker thermometer to detect water temp at any time.
  • 🐟 Easier installation, you can install it with any angle by 2 powerful suction cups, just make sure it is under water fully. Besides, we provide 1 more extra suction cup for spare (total 3 PCS), and we provide 12 months warranty.

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Best Seller #5

DaToo 50 Watt Aquarium Heater Submersible Adjustable Temperature Fish Tank Heater 50W

DaToo 50 Watt Aquarium Heater Submersible Adjustable Temperature Fish Tank Heater 50W

  • 🐠【50W DaToo Aquarium Heater】: A suitable temperature is very important for our beloved fish. No suitable temperature, our fish will not survive healthy. How to create this comfortable temperature? DaToo will help you. The DaToo Submersible Aquarium Heater is a system that create a warm and comfortable living environment for your lovely fish. Select DaToo Aquarium Heater, Let us care about your fish starting from the water temperature.
  • 🐠【Adjustable Temperature】: Only need turn the knob on the top of the DaToo fish tank heater, You can easily get the temperature you want(68 to 93°F) and you can read the temperature you set by the dial of the aquarium heater. Perfect Thermostat system to ensure that your beloved fish can be happy and comfortable life. Very Convenient !
  • 🐠【Sturdy And Durable】: Still worried about the heater will be broken?Now let’s say goodbye to this worry. The shell of the DaToo Aquarium Heater is made with Shatterproof, Corrosion resistant, Wear-resistant microcrystalline glass(glass-ceramics), can be used in fresh water and salt water.The heating part is made of nickel-chromium alloy, ensure superior heat transfer and enhanced service life. Select DaToo Fish Tank Heater, Let it serve your fish forever.
  • 🐠【BPA Free And Energy Saving】: Every plastic component of the DaToo Fish Tank Heater is made with durable, high-quality, BPA-free plastic. The process of heating does not produce invisible toxins. This means it is safe not only for your fishes, but for you as well. Stepwise heating mode, it will automatically turn on and off to keep your set temperature, reduce electricity consumption. Select DaToo Aquarium Heater, not only care about your fish, but also save electricity fee for you.
  • 🐠【Attention】: This is 50W DaToo Aquarium Heater, 7.6inch, fit 5 to 15 gallons tank with hoods or glass canopies and keep the water flowing. Please make sure that the heater is completely submerged in the water when using it. We provide One Year Warranty and 100% Money-back Guarantee. Select DaToo Products= Own A Private Aquarium Housekeeper.

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Best Seller #6

FREESEA 50W Mini Aquarium Heater Fish Tank Submersible Heater with LED Temperature Display

FREESEA 50W Mini Aquarium Heater Fish Tank Submersible Heater with LED Temperature Display

  • ★ Temperature range: 59°F~94°F, display Fahrenheit °F, this heater is designed for1~10 gallons tank. Upgrade function: The heater will auto shut off when it is out of water and turn normal when fully in water again.
  • ★ 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.
  • ★ Touch button, cyclic adjust temperature , easy to use and Safety.
  • ★【Note】:this heater is 100% submersible use only, during its heating time, heater must be 100% submerged into the water.
  • ★【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.

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Best Seller #7

PULACO 25W Small Aquarium Betta Heater with Free Thermometer Strip, Under 6 Gallon Fish Tanks (Preset Temperature 78℉)

PULACO 25W Small Aquarium Betta Heater with Free Thermometer Strip  Under 6 Gallon Fish Tanks (Preset Temperature 78℉)

  • ★【Betta Heater】This Fish Tank Heater should be 100% submerged into water, Ideal for small glass or acrylic desktop aquariums up 1 to 6 Gallons, not suitable for less than 1 gallon tank.
  • ★【Quick and Easy Installation】:Vertical or horizontal placement using, Aquarium heater automatic temperature control 78℉, no need to adjust temperature, easy to operate, fishes happy.
  • ★【How it Works】: Plug in, red light turns on, the heater will start working until water temperature up to 78°F, and red light off, then the green light will turn on, heater stop working and keeping constant temperature 78°F. Accuracy:±3°F
  • ★【Note】: Do not operate or leave product plugged in when your water tank is out of water, heater should be fully submerged into water. It is better to install a water pump to help water circulating while heating.
  • ★【SATISFACTION GUARANTEED】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.

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Best Seller #8

Marineland Precision Heater for Saltwater or Freshwater Aquariums

Marineland Precision Heater for Saltwater or Freshwater Aquariums

  • This 300 watt heater is for aquariums up to 80 gallons. Adjustable temperature dial allows you to set the temperature 1 degree with every click.
  • Thermal Switch automatically turns off as temperature rises above an internal preset and turns back on once it cools down.
  • The advanced heating element contains a mica core surrounded by a mesh heating element for superior heat transfer with enhanced durability
  • Advanced mounting bracket securely attaches to glass and provides 3 window positions to view the temperature display
  • Easy to view sliding scale tells the exact temperature setting. Top dial view shows the setting from an additional location.

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Best Seller #9

HiTauing Aquarium Heater, 50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic Power-Off When Leaving Water for Saltwater and Freshwater

HiTauing Aquarium Heater  50W/100W/200W/300W/500W Submersible Fish Tank Heater with Over-Temperature Protection and Automatic Power-Off When Leaving Water for Saltwater and Freshwater

  • 🐠【Rapid Heating and Two Temperature Control System】300W aquarium heater is sutable for 40-75 gallon fish tank and made of the most stable nickel-chromium heating wire, which can quickly and stably conduct heat to the surroundings. It has a built-in temperature control system of Fahrenheit and Celsius(Temp range: 63-94℉/17-34℃). You can press and hold the button next to the controller for 2-3 seconds to switch.
  • 🐠【Intelligent Water Sensor and Over Temperature Protection】This fish tank heater has a unique intelligent temperature and water sensor system, the heater will automatically stop heating when the heater is completely out of water or it rapidly heats beyond the set temperature, the indicator light will turn green in both cases to ensure the maximum safety of you and your aquatic organisms just like protecting our own safety.
  • 🐠【Explosion-proof Quartz Glass Aquarium Heater】The submersible aquarium heater is made of explosion-proof quartz glass material and a high-temperature resistant nickel-chromium heating wire with silicon carbide heat conduction, faster water heating and longer lasting. And the stronger black shell is a high temperature resistant ABS material which protect the fish, your aquatic organisms and you from scalding.
  • 🐠【Accurate External Digital Display Controller】The external IC temp controller of this aquarium water heater can show the water temp with 2 red LED digits. The temperature in Fahrenheit and Celsius is displayed, which can be switched by pressing and holding the button for a few seconds. To set the temp, just press the button over and over until the screen displaying the temp you desired, the setting is done and the led shows the current water temp again.
  • 🐠【Wide Range of Use】This 300 watt adjustable aquarium heater is suitable for many occasions. The fish market is a common place for us. It can maintain the freshness of fish. They are also suitable for places where aquatic life such as fish tanks, aquariums, and small fish ponds are kept. There are strong suction cups on the heater guard and the thermometer, it’s easy to install the aquarium heater no to the tank walls or bottom, please keep them fully submerged.

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Best Seller #10

Aqueon Small Aquarium Fish Tank Submersible Mini Flat Heater Up to 3 Gallon Aquariums, 7.5 Watts

Aqueon Small Aquarium Fish Tank Submersible Mini Flat Heater Up to 3 Gallon Aquariums  7.5 Watts

  • Fully submersible
  • Vertical or horizontal placement using suction cups that mount to the bottom or side wall of tank
  • Quick and easy installation
  • Shatterproof construction
  • Can be used with glass or acrylic enclosures
  • Note: Do NOT operate or leave product plugged in when it is outside of water
  • Warms aquarium water up to 6°F above ambient room temperature
  • 7.5 Watt works best for 1 to 3 gallon fish tanks

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Does My Aquarium Need a Heater?

If you’re keeping tropical fish as pets, they’ll likely need a heater to maintain water temperatures around 78-80°F. Most fish are cold-blooded animals that rely on their surrounding environment to regulate body temperature, so if your home is usually cooler, your fish will need a heater to remain comfortable.

Most aquarium fish can tolerate cooler temperatures than recommended because, in nature, the environment dips several degrees at night or during rainstorms. However, keeping the water at a steady warm temperature is less stressful on your fish and helps prevent diseases. Some species – like goldfish, Japanese icefish, and white cloud mountain minnows – enjoy cooler temperatures and would be fine without a heater. Other fish – like discus, ram cichlids, and certain Apistogramma cichlids – prefer hotter temperatures around 85°F and require a heater. By understanding the temperature preferences of the fish you’re trying to catch, you can better match the conditions of their natural habitat and improve your chances of success.

What Size Aquarium Heater Do I Need?

If you’re a fisherman, the general rule of thumb is 5 watts (W) of heat per 1 gallon of water if a) you need to heat the water to 10 degrees above room temperature, if you’re using an aquarium lid to retain warmth and prevent evaporative cooling. For example, if you have a 29-gallon tank under those conditions, the suggested heater size is 100 watts. However, if your home is on the colder side at 65°F and you need to raise the water temperature by 15 degrees, consider adding a second heater. This will ensure that your fish stay healthy and comfortable in their environment.

Recommended heater sizes for different types of aquariums:

Aquarium SizeHeater Size
5 gallons25W to 50W heater
10 gallons50W to 100W heater
20 gallons100W heater
29 gallonsOne or two 100W heaters
40 gallonsTwo 100W heaters
55 gallonsTwo or three 100W heaters
75 gallonsThree 100W heaters

Other factors that impact a fish tank’s temperature include its location in your home, how much sunlight the room gets, and whether or not it’s near an air conditioner. Additionally, because heat naturally rises, the tanks at the bottom of an aquarium rack will be cooler than the tanks at the top. Furthermore, equipment such as lighting and filtration contributes to the total heat produced in an aquarium. For example, a Fluval FX4 canister filter runs on 30 watts of power and therefore acts like a mini heater in your aquarium, slightly heating the water as it flows through the filter.

If you have a large tank that requires 200 watts of heat, we recommend purchasing two 100-watt heaters instead of one 200-watt heater. This way, if one heater malfunctions, it will not overheat the entire aquarium. Having two heaters also provides a backup in case one shuts off. This will prevent the water from getting too cold.

Where Should I Put My Aquarium Heater?

There are a few things to consider when deciding where to place your aquarium heater.

  • First, you need to ensure the heater is not in a place where it can be knocked over or damaged.
  • Second, you need to ensure the heater is not too close to any other objects in the aquarium so that heat can circulate properly.
  • Finally, you need to ensure the heater is not in a place where it will be in the way or difficult to reach.

With these things in mind, the best place to put your aquarium heater is usually on the back or side of the aquarium near the filter.

What to Consider When Choosing an Aquarium Heater

There are many aquarium heaters, but most of them function similarly. An aquarium heater typically has two main parts: a heating element and a thermostat. The heating element is usually made of metal and is responsible for generating heat. The thermostat is a temperature-sensitive switch that turns the heater on and off to maintain a consistent water temperature.

Thermostat

Most aquarium heaters have a built-in thermostat, but you can also buy separate thermostats that can be used with any type of heater. Aquarium heaters come in various sizes and shapes, so it is essential to choose one that is appropriate for the size of your aquarium. Smaller aquariums may only need a small heater, while larger aquariums may require a larger one.

Wattage

When choosing an aquarium heater, it is essential to consider the unit’s wattage. The wattage indicates how much power the heater uses and how much heat it can generate. Higher wattage means that the heater will use more electricity and generate more heat.

Size

When choosing an aquarium heater, it is also essential to consider the aquarium size. If the aquarium is too tiny, the heater may not be able to generate enough heat to keep the water at a consistent temperature. Conversely, if the aquarium is too large, the heater may use too much electricity and overheat the water.

Type

Finally, it is essential to consider the type of aquarium you have when choosing an aquarium heater. Freshwater aquariums require different kinds of heaters than saltwater aquariums. Be sure to select a heater designed for the type of aquarium you have.

Now that you know more about aquarium heaters, you can start shopping for the perfect one for your needs.

There are many aquarium heaters, but the most common type is the submersible heater that operates completely underwater. The water current helps spread the heater’s warmth to the rest of the tank. Ideally, the heater should be placed next to the filter output or pump for maximum flow. Install a thermometer in a corner opposite the heater to make sure the heat is reaching the other side of the tank. This will help ensure your fish are healthy and comfortable in their new home.

Some heaters must be positioned vertically, while others can lay down horizontally. For long, tube-shaped heaters, we recommend mounting the heater at a 45 degree angle to get the best heat distribution. You can conceal the heater by placing plants and decor in front of it or hiding it in the sump if you have one.

Do You Leave the Aquarium Heater on All the Time?

As a general rule of thumb, you should always leave your aquarium heater on. This will help to maintain a consistent water temperature, which is critical for the health and well-being of your fish. There may be times when you need to turn the heater off for short periods, such as when you are cleaning the tank or doing routine maintenance. However, as a general rule, it is best to always keep the heater on.

Yes, you could depart the heater 24/7. Aquarium warmers have an inner thermostat that turns off the warmth while it reaches a particular temperature; for this reason, preserving the water temperature inside some levels of the preferred setting.

When first putting in the heater, permit the device to acclimate to the aquarium water’s temperature for 20 to half-hour earlier than plugging it in, to save you breakage from temperature shock. Also, the heater should constantly be submerged in the water while it’s grown. (Sometimes, you’ll see a line at the heater that marks the minimal water level.) Otherwise, it can not appropriately study the water temperature and efficiently manipulate the heating. If you depart the heater jogging simultaneously as uncovered to dry air, it can burn out or crack, so don’t forget to unplug it or flip off the electricity strip while doing water changes.

Thankfully, warmers now no longer require a good deal of upkeep until you need to apply a toothbrush to softly scrub off algae. However, when you have to put off the heater for a few reasons, producers propose ready at least half-hour for it to settle down earlier than handling.

What Is the Best Aquarium Heater?

Out of all the supplies you need to buy when setting up a new fish tank, the aquarium heater is not one to skimp on. You want to find a good quality brand that is safe and reliable because unproven brands may fail by overheating, shutting down, or cracking – all with disastrous results. We personally would not recommend getting a used heater because you have no idea if the previous owner dropped it, left it running while out of water, and so forth.

We designed our own Aquarium Co-Op 100W heater with the goals of having excellent quality and a full range of features, such as:

  • The small, compact design makes the heater easier to position in the aquarium and hide behind decorations or rocks.
  • The digital display provides a large temperature reading that can be clearly read.
  • The heater guard is a protective plastic cage around the heater that prevents fish from wedging themselves and getting stuck behind the heater. (Yes, I’ve actually had fish die this way.) This enclosure also shields the heater from larger fish species that may crash into it. 
  • The adjustable temperature feature is useful in case you need to raise the temperature to treat diseases or lower the temperature to induce breeding. Unlike most heaters that use temperature dials, the Aquarium Co-Op heater has a simple button controller that is located outside of the fish tank so you don’t have to get your hands wet to change the temperature.
  • The extra-long, 11.8-foot power cable makes it possible to reach faraway wall outlets, even if you have a deep aquarium.
  • The suction cups allow you to firmly mount the heater onto the aquarium wall, and four extra suction cups are included as replacements.
  • The 1-year warranty and automatic over-temperature protection offers you peace of mind from heater malfunctions and manufacturing errors.

If you have a nano aquarium that holds 6 gallons or less, consider using the Fluval 25W submersible heater that is preset to maintain a temperature of 76-78°F.

Bottom line: don’t try to save money on heat. Give your aquarium fish a warm and comfortable home, and they’ll thank you for it with hours and hours of entertainment. 

Video Guide on “How to Choose an Aquarium Heater”

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