6 Best Aquarium Heaters of 2020

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Looking for the best aquarium heater? We’ve got you covered.

It’s official. Watching fish is good for your health.

Seeing beautiful fish and marine creatures swimming, feeding, and going about their daily lives is soothing and can reduce stress and high blood pressure.

For those of us who are passionate about keeping fish it can be very rewarding, so it’s natural that we want to provide our finned friends with the best living environment possible.

In order to do that they need to be keep in water that is the optimum temperature for their health — which is where an aquarium heater comes in…

What is an Aquarium Heater?

Fish are not able to produce their own body heat, instead relying on the temperature of the water around them to maintain their body temperature.

But installing an aquarium heater in your tank, you can maintain the water at a warm enough temperature for your fish to thrive.

aquarium heater installation

An aquarium heater is a tube shaped device containing a heating element, which is either placed directly in the tank or placed externally, and many models features a built in thermostat to regulate temperature .

Hanging aquarium heaters are normally suspended from the cover or hood of the tank to dangle into the water, with the heater controls being accessed via the part of the heater that sits outside the tank.

The glass heating element is protected in a fully sealed casing.

An alternative are submersible aquarium heaters which can be fully submerged in the water of the tank and are usually placed beneath the tank’s filter output to heat water as soon as it enters the aquarium environment.

In-line aquarium heaters on the other hand are totally external to the aquarium – usually placed in a plumbing feature such as a filter.

They require a pump to function, which pushes water out of the tank to be heated by the the in-line filter as it passes through it, and which then pumps the heating water back into the aquarium.

Lastly, substrate heaters are placed beneath the gravel or other substrate in the tank and gently warm the water using heated metal wires.

Is an Aquarium Heater Necessary?

In general, an aquarium will require a heater for tropical fish which typically need a water temperatures of 73 to 82 degrees or thereabouts, but temperate or freshwater fish should be fine without one.

It important to note that hanging heaters can be dangerous in salt water aquariums and they may corrode causing them to short out.

The size of aquarium heater you need will depend on the size of your aquarium. The larger the volume of water in your tank, the longer it will take to cool down, so will require a heater fewer watts.

Generally it is recommended to you have between 2.5 and 5 watts per gallon of water volume, although this is also dependent on the temperature of the surrounding environment.

Most aquarium heater manufacturers clearly state what size tank their heaters are suitable for.

Aquarium Heater Installation

Once you’ve purchased your aquarium heater, you will need to install it correctly.

Submersible and hanging heaters are most commonly placed inside the tank where the water flows through the filter intake, heating the clean water as soon as it arrives in the tank and dispersing it more evening throughout the entire aquarium.

Suction cups are usually used to hold the heater in place on the internal surface of the glass.

Depending on the needs of your particular fish, you must set the appropriate temperature, and then leave it in the tank for at least 20 minutes to ensure the glass casing is fully adjusted to the current water temperature before firing the heater up.

If you’re not convinced that your aquarium heater is working properly, first check to see that the monitor light is on — if it is then the heater is most likely working.

If you’re still not sure, check the water temperature every 6 hours or so in order to see if it is staying within the desired range.

It is a good ideal to regularly clean the outside of the aquarium heater with a scrubbing brush and warm water to ensure it is in optimum working order, as salt, algae and mineral build up can be damaging and impair the heater from functioning correctly.

Also check regularly for cracks or other damage which usually means that the heater needs replacing.

best aquarium heater

Are Aquarium Heaters Safe?

Worried about safety? Although it is possible, cases of fish, glass, or aquarium decor being burned by aquarium heaters are rare, although many fish keepers choose to invest in an aquarium heater guard to prevent this from happening.

Remember to always unplug the heater when doing aquarium water changes or if removing it from the water.

What to Look for in a Good Aquarium Heater

Adjustable temperature

Believe or not some aquarium heaters don’t have an option to change the temperature, so be sure that you are able to regulate the heat level on the heater you choose.


Constantly manually regulating water temperature can be tiresome, and becomes even more an issue if you go away on vacation.

An aquarium heater with a built in thermostat will regulate temperature automatically without you lifting a finger — plus it keeps temperatures super stable.

Safety features

Stay safe. Choose a heater made from shock or shatter proof glass, and preferably with an automatic cut off feature for when it is out of the water or in the event that the water level unexpectedly drops.


Heaters with built in controls should be designed in a way that makes the controls easily accessible at all times and not fiddly to use.

Quality and durability

I’ve heard some real horror stories about cheap aquarium heaters going wrong, so it’s worthwhile investing a little more in a heater manufactured by a reliable brand using quality components. They’re also much more likely to last much longer than cheaper models.

The Best Aquarium Heaters

Hygger Submersible Fish Tank Heater

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Suitable for aquariums between 30 and 60 gallons in capacity, the 300 Watt Hygger submersible fish tank heater is made from heat resistant quartz which is guaranteed not to crack or burst.

Whether you’ve got a salt water or fresh water aquarium this heater is suited to both, and the compact design features safety features such as a removable heater guard and automatic shut off.

The practical adjustable temperature control dial is situated external to the aquarium, and is accurate to within 2° F.


  • Attractive design
  • Good safety features
  • Conveniently placed temperature controller
  • Affordable
  • Accurate


  • Suction cups sometimes slip if not properly adhered

best aquarium heater

Aqueon Pro Adjustable Heater

best fish tank heater

Available in various sizes from 50 to 300 watts, these aquarium heaters by Aqueon are suitable for most home tanks holding from 5 up to 90 gallons.

Submersible, shatter proof and encased on thermal plastic to protect against damage and wear and tear, this heater is built to last.

The temperature control dial can be easily accessed, and the electronic thermostat effortlessly regulates desired temperature and is accurate to within 1°F.

There is an automatic shut off feature in the unlikely event that the Aqueon should overheat. The Aqueon Pro adjustable heater can be used in both fresh and salt water aquariums.


  • Features a handy thermostat
  • Comes with lifetime warranty
  • Easy to install
  • Very durable
  • Elegant design
  • Efficient and well made


  • Not as durable as the Hygger heater above

best aquarium heater

Zacro AH476 Submersible Aquarium Heater

best heater for aquariums

Bursting with features for the low price, the Zacro AH476 Submersible Aquarium Heater comes complete with protective plastic guard and a high quality power cable with attached thermostat to allow you to regulate water temperature without getting your hands wet, and temperatures are easily visible on the convenient LCD display.

This 300 watt heater is capable of heating tanks with a water volume of between 53 to 80 gallons.


  • Easy to set up
  • Comes with handy thermometer
  • LCD screen makes reading and setting temperature simple
  • Takes up very little space
  • Protective heater guard
  • Affordable price


  • Indicator lights and LCD display are distractingly bright
  • No automatic safety shut off feature

best aquarium heater

Fluval E Electronic Heater

electronic heater for fish tankare aquarium heaters safe

Fluval’s clever, color coded VueTech technology means you can see any water temperature changes in your aquarium at a glance with the Fluval E heater.

The unit features an LCD screen which clearly shows the temperature and is which changes color from green to red or blue if the temperature rises or drops, and flashes if the temperature changes drastically.

The desired temperature can be set easily and accurately using the adjustment lever, and there is a sturdy heater guard to protect from damage.

There are Fluval E heaters available for many different sizes of aquarium, from 15 gallons to 100 gallons.


  • Quality manufacture
  • Innovative temperature LCD monitor
  • Comes with 5 year warranty
  • Precise temperature settings
  • Good for both fresh and salt water aquariums


  • Is quite a large heater which may limit placement
  • Complex set up

best aquarium heater

Eheim Jager Aquarium Thermostat Heater

aquarium heatersbest aquarium heater

Made using glass specially designed not to shatter — even in extreme heat fluctuations — and featuring a conveniently placed temperature dial accurate to within 0.5°F, plus a thermostatic safety control that cuts the current if the heater is out of the water- – the Eheim Jager Aquarium Thermostat Heater is one of the most popular submersible aquarium heaters available.

Available in a wide range of sizes from 25 to 300 Watts, the Eheim heater fixes easily to the side of the aquarium using suction cups, and benefits from an indicator light to let you know that it is in full working order.


  • Safety shut down feature if too hot or too dry
  • Precise temperature dial
  • Convenient long power cable
  • Huge range of Watts to fit different sized tanks
  • Can be used in fresh or salt water
  • Shock resistant


  • No heater safety guard
  • Long length can be inconvenient when placing the product

best aquarium heater

Hygger Titanium Aquarium Heater for Salt Water and Fresh Water

best aquarium heateraquarium heater installation

Another submersible aquarium heater by Hygger, the heating element of the Hygger Titanium Aquarium Heater is made from long lasting titanium, which is ideal for marine tanks as it is resistant to salt water, and is easy to keep clean.

Available in 50, 100, and 200 Watt sizes, this heater features a compact design and benefits from a practical external thermostatic temperature control with LED screen, which shows the current water temperature as well as the set temperature.

Temperature control accuracy is to within 1℉.


  • Corrosion resistant
  • Small size makes it easy to conceal
  • User friendly temperature control box
  • Wide temperature range
  • Good temperature accuracy


  • Cannot be used with a sump
  • Cannot be placed underneath a substrate

best aquarium heater

What’s your pick for the best aquarium heater?

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