Aquarium Heaters
Fish are not able to self-regulate their body temperature. They require their water environment to do this for them.
This poses two main challenges:
- The water temperature needs to be in line with their natural environment
- Temperature fluctuations (even if around the ideal temperature) will cause the fish stress
Controlling the temperature of the aquarium is therefore very important. Especially for many of the tropical species that are kept in freshwater aquariums.
Do you Even Need An Aquarium Heater?
You aquarium will naturally take on the same temperature as the ambient temperature. The ambient temperature in a room will normally fluctuate during the course of a day (warmer during the day and cooler at night). The water temperature will also naturally fluctuate, but slower than the ambient air temperature.
As a good approximation, the average water temperature of your aquarium will be equal to the average air temperature. This poses a problem for many fish keepers – their fish often come from a tropical habitats. They therefore need to heat the water to make their fish more comfortable.
Using an aquarium heater has the added advantage of helping to minimize the fluctuations in water temperature.
So… what type of fish do you have? And what is the average temperature of a water when it is left in your room? To measure this, simply take 3 (or more) measurements evenly over 24 hours and take the average. This will let you know how much (if at all) you need to heat the aquarium water to bring it to the optimum temperature
Once you know this you can then select the aquarium heater that is most suited for heating your body of water to the correct temperature (and keeping it there).
Some users may find (particularly if they live in a hot country and own non-tropical fish) that they actually have to cool the natural water temperature down. This is possible through a range of aquarium coolers.
25 Watt Aquarium Heaters
PGFUNNY 25W Aquarium Heater, with Thermometer Strips
A Little Bit Fishy Score: 4/5
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This PGFunny 25 Watt aquarium heater is great for 3 to 5 gallon fish tanks. The heater is submersible and has a slim design – perfect for heating smaller aquariums. Suction cups enable you to attach the aquarium heater to the wall of the fish tank.
The heater is preset to keep the water between 77 and 82 degrees Fahrenheit (25 to 28 degrees Centigrade). This is a great range for tropical fish and means that you don’t have to worry about setting it at the correct temperature. The heater will switch on / off accordingly if the temperature moves outside of this range. The heater also comes with thermometer strips that allow you to monitor the temperature within your tank.
The automated temperature setting can be great for those looking for a simple yet effective solution. However, it the heater comes with 2 main disadvantages:
- Not being able to set the specific temperature. It is therefore not possible to adjust the temperature if you want to add different fish (or use the heater in a breeding tank).
- The 5 degrees Fahrenheit temperature range is not ideal. More technical heaters are able to keep the temperature variation within one degree (or less).
Overall the PGFunny 25 Watt aquarium heater is a cost effective option for those looking to heat a 3-5 gallon fish tank. It’s simplicity makes for easy installation, but those looking for more control over the temperature may with to consider another option.
NICREW Submersible Betta Fish Tank Heater
A Little Bit Fishy Score: 4/5
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This NICREW submersible Betta aquarium heater works for aquariums up to 5 gallons. It has a safety feature to shut off heating automatically if it is removed from water.
The heater is preset to heat the water to 78 degrees Fahrenheit (26 degrees Centigrade). This is a great temperature for tropical fish and means that you don’t have to worry about setting it at the correct temperature. The heater will switch on / off accordingly if the temperature moves outside of this range. A LED indicator light displays red when actively heating.
The automated temperature setting can be great for those looking for a simple yet effective solution. However, it does mean that it is not possible to adjust the temperature if you want to add different fish (or use the heater in a breeding tank).
Overall the PGFunny 25 Watt aquarium heater is a cost effective option for those looking to simply warm up their Betta fish tank. It’s simplicity makes for easy installation, but those looking for more control over the temperature may with to consider another option.
Fluval Marina Submersible Heater for Aquarium, Mini
A Little Bit Fishy Score: 4/5
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This Fluval Marina submersible 25 Watt heater is perfect for 5 gallon fish tanks. The heater is submersible and has a slim design – perfect for heating smaller aquariums. It comes with a bracket and suction cups for easy attachment to your tank. Unlike the two previous options discussed, the Fluval comes with the ability to set the desired temperature.
We like the Fluval:
- It is still economical compared to other heaters with similar capabilities
- It is compact, ensuring that it does not become an eyesore even within a 5 gallon tank
- Unlike other options in its price range, it has an adjustable temperature feature.
But bear in mind that:
It is designed for up to 5.5 gallon tanks only. If you tank is larger (or indeed if your ambient temperature is very low) you might be better off with a 50 Watt model.
Overall the Fluval Marina submersible 25 Watt heater is a great option for those looking for an economical way to adjust the temperature of a tank up to 5 gallons in size.
50 Watt Aquarium Heaters
Hygger 50W Submersible Digital Aquarium Heater
A Little Bit Fishy Score: 4.5/5
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The Hygger 50W submersible digital aquarium heater is perhaps the best 50 Watt heater available today. It is an oval shape design, avoiding the elongated design of other producers that can become an eyesore. The heater works quickly and can be used on tanks up to 6.5 gallons in size. There is also a 100W version for 6.5-13 gallon aquariums.
The heater is 2.7×1.4x 4.5 inches in size and has a power cord which is 5 feet long. The external controller allows you to set the temperature from 63 to 94 degrees Fahrenheit (17-34 degrees Centigrade). One benefit of this controller is that you don’t have to put your hand into the tank every time you want to change the temperature! The heater has good accuracy – it heats the aquarium to within 1 degree of the temperature set.
The heater comes with 2 suction cups that allow for easy attachment to your fish tank. There is also a LED display showing you the current temperate in the tank and a light to indicate when the heater is actively heating the water.
The heater is fully submersible. As a safety precaution it will stop heating when removed from the tank. Heating function will resume when replaced in the tank.
Overall the heater is easily adjustable, well priced and reliable. Definitely a good choice for those wanting to heat an aquarium up to 6.5 gallons in size.
Aqueon Adjustable Aquarium Heater, 50 W
A Little Bit Fishy Score: 4/5
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The Aqueon adjustable 50 watt aquarium heater is suitable for aquariums up to 20 gallons in size. It is a fully submersible design and is made of quartz and glass to ensure it is shatter resistant.
The water temperature can be adjusted to between 68 and 88 degrees Fahrenheit (20 to 31 degrees Centigrade). It has an accuracy of +- 1 degree Fahrenheit. There is a power light to indicate whether the heater is actively heating the tank. Further, the heater has automatic shutoff safety feature.
Fluval M50 Submersible Aquarium Heater
A Little Bit Fishy Score: 4/5
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The Fluval M50 submersible aquarium heater is suitable for tanks up to 15 gallons in size. It has reflective properties that help it to blend into the tanks (by taking on the appearance of the surrounding colors).
The heater has a slimline profile and is easy to install. It has shock resistant Borosilicate glass, a high density ceramic heating component and is known for its durability. The Fluval M50 comes with a 3 year warranty.
Overall the heater offers good value for money. One thing to be aware of, is that if your ambient temperature is on the low side (say 60 Fahrenheit) then the heater may be better for a 5-10 gallon tank rather than trying to heat a 15 gallon tank.
100 Watt Aquarium Heaters
Hygger Saltwater Tank Submersible Aquarium Heater – 100 Watt
A Little Bit Fishy Score: 4.5/5
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The Hygger 100 watt submersible saltwater aquarium heater is suitable for 10 to 25 gallon aquariums. It should be placed horizontally within the tank and comes with 2 suction cups to easily mount it on the tank.
As with other heaters, it should be placed in an area of the tank that has good water flow. This assists in ensuring that the tank is evenly heated throughout.
The heater comes with an external temperature control – no need to get your hands wet! The temperature can be set from 32 to 104 Fahrenheit, although much of this will be outside the range that you’ll want to use.
The heater is made from titanium and has no glass in the design. This removes the risk of the heater shattering and it great for ensuring the durability of the product. Due to the durability of the product, it is suitable for both saltwater and freshwater aquariums.
Overall, the Hygger 100 watt submersible saltwater aquarium heater is a high quality and durable product. It is easy to set up and a great option if you need to heat an aquarium of 10 to 25 gallons in size.
Uniclife 100 W Aquarium Heater for 20 Gallon Fish Tank
A Little Bit Fishy Score: 4/5
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The Uniclife 100 W aquarium heater is great for 10 to 25 gallon fish tanks. It can be used for both freshwater and saltwater aquariums.
Unlike the Hygger model, it does not have a digital display. The water temperature can be adjusted between 68 and 93 degrees Fahrenheit by twisting the dial at the top of the heater. A red light indicates when the heater is actively heating the water.
The heater can be attached to the tank either horizontally or vertically using 3 suction cups provided. strong suckers tightly fix the heater to the tank vertically or horizontally, the red indicator light on while working. It is 9.7 by 1 inch in size.
Fluval M100 Submersible Aquarium Heater
A Little Bit Fishy Score: 4/5
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The Fluval M100 submersible aquarium heater is suitable for tanks up to 30 gallons in size. It has reflective properties that help it to blend into the tanks (by taking on the appearance of the surrounding colors).
The heater has a slimline profile and is easy to install. It has shock resistant Borosilicate glass, a high density ceramic heating component and is known for its durability. The Fluval M100 comes with a 3 year warranty.
Overall the heater offers good value for money. One thing to be aware of, is that if your ambient temperature is on the low side (say 60 Fahrenheit) then the heater may be better for a 20 gallon tank rather than trying to heat a 30 gallon tank.
200 Watt Aquarium Heaters
Hygger Saltwater Tank Submersible Aquarium Heater – 200 Watt
A Little Bit Fishy Score: 4.5/5
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The Hygger 200 watt submersible saltwater aquarium heater is suitable for 20 to 45 gallon aquariums. It should be placed horizontally within the tank and comes with 2 suction cups to easily mount it on the tank.
As with other heaters, it should be placed in an area of the tank that has good water flow. This assists in ensuring that the tank is evenly heated throughout.
The heater comes with an external temperature control – no need to get your hands wet! The temperature can be set from 32 to 104 Fahrenheit, although much of this will be outside the range that you’ll want to use.
The heater is made from titanium and has no glass in the design. This removes the risk of the heater shattering and it great for ensuring the durability of the product. Due to the durability of the product, it is suitable for both saltwater and freshwater aquariums.
Overall, the Hygger 200 watt submersible saltwater aquarium heater is a high quality and durable product. It is easy to set up and a great option if you need to heat an aquarium of 20 to 45 gallons in size.
Fluval M200 Submersible Aquarium Heater
A Little Bit Fishy Score: 4/5
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The Fluval M200 submersible aquarium heater is suitable for tanks up to 65 gallons in size. It has reflective properties that help it to blend into the tanks (by taking on the appearance of the surrounding colors).
The heater has a slimline profile and is easy to install. It has shock resistant Borosilicate glass, a high density ceramic heating component and is known for its durability. The Fluval M200 comes with a 3 year warranty.
Overall the heater offers good value for money. One thing to be aware of, is that if your ambient temperature is on the low side (say 60 Fahrenheit) then the heater may be better for a 50 gallon tank rather than trying to heat a 65 gallon tank.
300 Watt Aquarium Heaters
Hygger 300 Watt Aquarium Heater with Digital Temperature Controller
A Little Bit Fishy Score: 5/5
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The Hygger 300 Watt aquarium heater is one of the best heaters available for 30-60 gallon tanks. The heater is fully submersible. It comes with heat protection, and shuts off in the event of overheating, resetting once it has cooled down.
The heater is made with premium quartz and also comes with a protective guard. This double layer of protection helps ensure durability of the heater and also serves to protect your fish from a malfunctioning heater.
The temperature display has an easy to read screen. This is driven by the Hygger’s in-built temperature monitor and controller. Additionally, there are indicator lights to let you know when the heater is actively heating the water.
The temperature can be adjusted from outside the tank – no need to get your hands wet each time! It can be set from 61 to 90 degrees Fahrenheit (16 to 21 degrees Centigrade). It’s temperature is accurate to within 1 degree Fahrenheit of the set temperature.
Overall, the Hygger 300 Watt aquarium heater is a high quality heater. It is one of, if not the, best options for safely and easily heating your 30 gallon, 55 gallon or even 60 gallon aquarium.
ZEETOON 300W Aquarium Heater for Salt or Fresh Water
A Little Bit Fishy Score: 4/5
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The ZEETOON 300W aquarium heater is suitable for both saltwater and freshwater aquariums. It is a fully submersible heater which also comes equipped with a digital thermostat. It is most suitable for glass aquariums up to 80 gallons in volume.
The heater is capable of maintaining temperatures of 68 to 93 Fahrenheit (20 to 34 degrees Centigrade). It works to an accuracy of within 2 Fahrenheit of the set temperature. In order to maintain the most even temperature across your tank, the heater should be installed in or near water flow (such as the exit of your filter) so that the heater is distributed evenly.
The heater is made form a high quality titanium alloy. This has several benefits:
- It helps prevent corrosion – particularly important if you are using it in a saltwater aquarium
- It minimizes the chances of the heater cracking and thereby causing harm to your fish
The temperature setting can be manually adjusted from outside the tank. The heater will automatically turn on and off to maintain the aquarium water at the desired temperature. Additionally, for safety purposes, it will shut off automatically when removed from water.
Overall the ZEETOON 300W aquarium heater is worth considering for both fresh and saltwater aquariums up to 80 gallons in volume.
500 Watt Aquarium Heaters
Hygger 500 Watt Aquarium Heater with Digital Temperature Controller
A Little Bit Fishy Score: 5/5
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The Hygger 500 Watt aquarium heater is one of the best heaters available for 60-120 gallon tanks. The heater is fully submersible. It comes with heat protection, and shuts off in the event of overheating, resetting once it has cooled down.
The heater is made with premium quartz and also comes with a protective guard. This double layer of protection helps ensure durability of the heater and also serves to protect your fish from a malfunctioning heater.
The temperature display has an easy to read screen. This is driven by the Hygger’s in-built temperature monitor and controller. Additionally, there are indicator lights to let you know when the heater is actively heating the water.
The temperature can be adjusted from outside the tank – no need to get your hands wet each time! It can be set from 61 to 90 degrees Fahrenheit (16 to 21 degrees Centigrade). It’s temperature is accurate to within 1 degree Fahrenheit of the set temperature.
Overall, the Hygger 500 Watt aquarium heater is a high quality heater. It is one of, if not the, best options for safely and easily heating your 60-120 gallon aquarium. Perfect for a 100 gallon fish tank!
ZEETOON 500W Aquarium Heater 40-120 Gallon
A Little Bit Fishy Score: 4/5
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The ZEETOON 500W aquarium heater is suitable for both saltwater and freshwater aquariums. It is a fully submersible heater which also comes equipped with a digital thermostat. It is most suitable for glass aquariums up to 120 gallons in volume.
The heater is capable of maintaining temperatures of 68 to 93 Fahrenheit (20 to 34 degrees Centigrade). It works to an accuracy of within 2 Fahrenheit of the set temperature. In order to maintain the most even temperature across your tank, the heater should be installed in or near water flow (such as the exit of your filter) so that the heater is distributed evenly.
The heater is made form a high quality titanium alloy. This has several benefits:
- It helps prevent corrosion – particularly important if you are using it in a saltwater aquarium
- It minimizes the chances of the heater cracking and thereby causing harm to your fish
The temperature setting can be manually adjusted from outside the tank. The heater will automatically turn on and off to maintain the aquarium water at the desired temperature. Additionally, for safety purposes, it will shut off automatically when removed from water.
Overall the ZEETOON 500W aquarium heater is worth considering for both fresh and saltwater aquariums up to 120 gallons in volume.