Best Aquarium Heaters in the UK

Review & Comparison, Last Update January 19, 2024
Aquarium heaters are necessary to make sure tropical fish species are able to survive and thrive in captivity. The best aquarium ...Read more
PROS

The sizable LED screen will make the temperature visible from 3-5 metres. The red light will tell you that the water temperature has not reached the set range yet, while the blue light will indicate that it is within the programmed set range. Its intelligent IC chip will minimise the error margin, keeping it below ±1°C/±2°F.

CONS

The model makes loud whistling noises whilst working. 

OUR VERDICT

Besides aquariums, this capable unit from POPETPOP will also be able to accommodate reef tanks ranging from 150 to 350 litres. Its upgraded sensory probes will ensure precise induction, so you know that the displayed temperature is always accurate. 

detailed parameters
Type

Submersible

Compatibility

Freshwater and saltwater aquariums, reef tanks 

Aquarium Volumes

Water tanks: 150 - 350 litres

Aquariums: 100 - 120 litres

Power

400 W

Temperature Regulation

20°C - 34°C 

Protection

Explosion-proof, waterproof, and scald-preventing housing, over-temperature and dry protection

Warranty

Amazon's 30-day return policy

PROS

The cable measures almost 3 metres, so you will not be quite as tied to the outlet as you usually are with aquarium heaters. The dual digital display windows let you view and set the temp with practically nonexistent ambient light. The housing's non-friable and protected from cracking.

CONS

The suction cups are not very grippy. 

OUR VERDICT

The U-Picks Submersible Fish Tank Heater is as convenient for you as it is for the fish inside the aquarium. Employing stepwise heating, this unit makes sure the temperature is rising gradually, preventing the water from becoming too warm too fast and making little fishies uncomfortable.

detailed parameters
Type

Submersible

Compatibility

Freshwater and saltwater aquariums 

Aquarium Volumes

30 - 300 litres

Power

300 W

Temperature Regulation

20°C - 34°C

Protection

Explosion-proof quartz tube (anti-cracking and non-friable), corrosion-resistant and waterproof housing, over-temperature protection

Warranty

Amazon's 30-day return policy

PROS

The model lets you easily adjust the temperature via the click-control dial that's been put atop the unit. But the heater arrives already pre-set to 24°C, so, chances are, most people will not even need to adjust the temperature since that's the temperature that suits most tropical fishes. 

CONS

The mains lead is short. 

OUR VERDICT

The Interpet Deltatherm Aquarium Heater will enable precise heating control without you paying through the nose. The unit will accommodate freshwater, saltwater, and tropical aquariums. The high-strength glass is both shock- and shatter-resistant.

detailed parameters
Type

Submersible

Compatibility

Freshwater and saltwater aquariums 

Aquarium Volumes

135 - 270 litres

Power

300 W

Temperature Regulation

20°C - 34°C

Protection

Waterproof, heat-, shatter- and shock-resistant glass housing, over-temperature protection

Warranty

2 years

PROS

The 3 suction cups will prevent the unit from moving even when considerable force is applied. The 8-slot multi-branched heating wire ceramic frame will improve heat dissipation and make sure the heat is spread evenly. 

CONS

The thermostat is not entirely accurate. 

OUR VERDICT

Drawing less than 100 watts, the HITOP HP-608 Aquarium Heater will not increase the energy bills but will still be able to support aquariums between 50 and 150 litres. The model will also let you adjust the temperature between 20°C and 34°C.

detailed parameters
Type

Submersible

Compatibility

Freshwater and saltwater aquariums

Aquarium Volumes

50 - 150 litres

Power

100 W

Temperature Regulation

20°C - 34°C

Protection

Explosion-proof quartz tube, waterproof housing, over-temperature protection

Warranty

2 years

PROS

The glass housing is 1.5 millimetres thick, making the unit not just waterproof but also blast-proof. The heater will automatically shut down when the temperature starts going above the pre-set range. A red light will display the unit's status. 

CONS

The display gets fogged up. 

OUR VERDICT

The XiLONG 300W Aquarium Heater will allow you to set the temperature anywhere between 17 and 35°C. Covering aquariums that range from 200 to 300 litres, this affordable heater will let you make your favourite fishes comfortable without spending more money than you're comfortable with.

detailed parameters
Type

Submersible

Compatibility

Freshwater and saltwater aquariums 

Aquarium Volumes

200 - 300 litres

Power

300 W

Temperature Regulation

17°C - 35°C

Protection

Waterproof and blast-proof glass housing, over-temperature protection

Warranty

Amazon's 30-day return policy 

Fitting Reef Tanks as Well

The POPETPOP 400W Aquarium Heater highlights its biggest strength with the name from the get-go. Drawing and outputting 400 watts, this model is much more capable than most aquarium heaters that are usually capping at ~300 watts. Using sensing probes, this model provides precise induction, making sure that you can always check the temperature knowing that the measurements are accurate. To add more, the unit uses nickel-chromium wire, making its housing more durable and stable than glass heaters. These high-quality materials make the model explosion-proof, waterproof, and scald-preventing.

From a convenience perspective, the LED screen displays the water temperature, with the red light telling you that the temperature is below the set range and the blue light showing that it is within the desired set range. In the meantime, the intelligent IC chip enables the aforementioned precise temperature control and minimises the margin of error (±1°C/±2°F). finally, the touch-button lets you adjust the temperature without getting your hands wet.

In closing, with its high output and heavy-duty materials, this model from POPETPOP fits not just aquariums but also reef tanks between 150 and 350 litres.

Last updated price £40.77
Stock In stock
ASIN B07YV7QZBH

Dual Digital Display Windows

The U-Picks Submersible Fish Tank Heater is about its dual digital display windows before anything else. With these windows, you can tell the water temperature with excellent clarity and set the temperature even in low-light conditions at the same time. Plus, using an external temperature controller, you'll be able to adjust the temperature without putting the hand in the tank, which is also quite convenient.

Still, one would argue that its biggest selling point is the quartz glass construction, making the housing blast-proof, waterproof, corrosion-resistant, protected against cracking, and non-friable, preventing electricity leakage.

Using stepwise heating, the unit makes the temperature rise gradually, preventing the temperature from changing with unnecessary expedience and making the fish inside the tank uncomfortable. But, even though this feature will sound less impressive, the long cable also drives the product's value forward, not keeping you as tied to the mains as most aquarium heaters.

The suction cups are where the product cuts corners. Though they're fine initially, the cups become a less loss grippy eventually. But, even taking this problem into account, the U-Picks Submersible Fish Tank Heater blows most of its competition out of the water (pun intended).

Last updated price £26.99
Stock May be out of stock
ASIN B0825S2RPV

Precise and Reliable Heating Control

The Interpet Deltatherm Aquarium Heater enables affordable yet precise and reliable heating control, accommodating freshwater, marine, and tropical aquariums alike. With its easily accessible click-control dial atop the heater, you can set the temperature with precision but, chances are, you won't even need to do so since the unit comes pre-set to 24 degrees Celcius, the temperature that fits most tropical fish species.

Having said that, the product's most attractive quality is the double-insulated glass housing that makes the unit heat-, shock-, and shatter-resistant, enabling long-term use without worrying that the heater might break and cause some damage. The least attractive quality is that the cable here is short, so you cannot position the aquarium 2+ metres away from the mains.

Of course, the housing is also waterproof and features over-temperature protection. Accommodating aquarium volumes between 135 and 270 litres, this unit easily covers everyday customers needs, with the heating element drawing and outputting 300 wats.

In other words, with this heater, you can rest assured knowing that your beloved fish are safe, sound, and warm inside the aquarium, all without you spending more than 20 quid.

Additional Info

User Manual

Last updated price £21.95
Stock In stock
ASIN B003VZFP6K

Covering Small Aquariums' Needs

The HITOP HP-608 Aquarium Heater is the most humble unit within this selection. Drawing (and outputting) just 100 watts, the model will cost you nothing long-term (from an energy consumption perspective) but, needless to say, with this output, will also be unable to maintain aquariums above 150 litres.

Besides that, the people behind this product are claiming that the unit is offering high-precision temperature control, and whilst that is not necessarily inaccurate, the thermostat does not always display the right temperature, giving you an error margin around ±1-2 degrees. Still, you can adjust the temp between 20 and 34 degrees Celcius, which is pretty good. But what's more impressive is the 8-slot multi-branched heating wire ceramic frame, improving the model's heat dissipation and ensuring stability.

Not unlike more expensive heaters, the quarts tube on this one is explosion-proof and the housing's waterproof. Plus, you receive a spare stick-on thermometer and an extra suction cup, so an already affordable package is even more attractive than you initially reckon.

Bottom line, people with small and medium-sized aquariums should, at the very least, look towards this model's direction.

Last updated price £13.97
Stock In stock
ASIN B07PNY5BFV

Almost no Trade-Offs

The XiLONG 300W Aquarium Heater is the least expensive model within this lineup, which is quite impressive considering that its specs are up there with the more expensive heaters. To name a few, this unit maintains aquariums measuring from 200 to 300 litres capacity-wise, drawing the same 300 watts that the less capable heaters are drawing. Its temperature range is a little more expansive, letting you set the temp between 17 and 35 degrees Celcius. The trade-off is that the display can get fogged up, so you'll have to get your hands get sometimes to clear it up.

But as far as construction is concerned, there are no trade-offs here, with the 1.5-millimetre glass making the unit blast-proof as well as waterproof. Aso, mirroring its less affordable competition, the model features over-temperature protection, with a mechanism that automatically shuts down the heater when the temperature goes above the pre-set range.

Wrapping the subject, the unit comes equipped with a red light that displays its status and lets you know that the heater is working from a distance. So, if you want an affordable aquarium heater that can cover and maintain sizable aquariums, what we have here is an excellent pick for you.

Last updated price $0.00
Stock In stock
ASIN B07LBWJ13C

What Is an Aquarium Heater?

Aquariums are underrated. Seriously, they are. There are many reasons to keep fish, including various health benefits. Watching these majestic aquatic creatures swim there helps you relax and maintaining the tanks where these creatures live gives you purpose and reason to get out of bed in the morning.

Before anything else though, these aquariums require aquarium heaters. More often than not, tropical fish cannot survive without these water heaters keeping the temperature nice and warm. Fortunately, these heaters are not that difficult to choose, and we've broken down these difficulties in the What Features to Compare section, so you should have no issues figuring out the right unit.

Apart from everything we've described in that section, we would also recommend making sure that the unit's size won't be able to obstruct the view, so look into models with slim profiles and the ones you can position vertically first and foremost.

Other than that, we would recommend looking into these water filter systems and alkaline water ionizers to make sure you're able to supply the aquarium with clean water.

What Features to Compare

Type

First, you have to figure out the heater's type. Generally speaking, these heaters are categorized into in-line external heaters and submersible heaters. As you'd imagine, the differences between these units are obvious and straightforward.

The only thing we'd like to mention is that, when you choose submersible heaters, make sure that the unit comes with an external controller so that you're able to change the temperature without taking out the heater and/or getting your hands wet. Apart from that, most small tanks and large tanks have no issues with both heater types.

Compatibility

This one can be important, even though most models are compatible with most aquariums. Generally speaking, aquarium heaters are able to support most freshwater tanks, saltwater aquariums, reef tanks, and sometimes, even different glass containers and hydroponic systems.

Volume Range

This is where you have to pay extra attention. These heaters go from 1-2 to 100+ gallons, meaning that some might not even be enough to support most small aquariums, while other models will have no issues with large tanks. Make sure that the heater you're looking to purchase will be able to accommodate your aquarium's volume.

Power

Needless to say, these heaters are not mechanical devices, meaning that they're drawing and outputting watts. Generally speaking, the unit's output will tell you how quickly it will be able to heat up the entire aquarium and how large these aquariums can be but these numbers can be misleading, so we would not recommend relying on them to tell the whole story.

Temperature Regulation

Mid-range and high-end aquarium heaters will let you regulate the water temperature inside the tank. Sometimes, you'll be able to do that via separate controllers. Sometimes, you'll have to dunk your hand inside the tank to access these settings.

More often than not, these heaters let you adjust the temperature somewhere within the 65 - 95 degrees Fahrenheit range.

Occasionally though, you'll be able to change the temperature somewhere from 30 to 100 degrees but these heaters are rare.

Budget models come with pre-set temperatures somewhere around 78 degrees and you cannot change that.

Protection

Most aquarium heaters come equipped with an automatic shut-off feature that makes sure these units do not overheat. Sometimes, there are also various anti-corrosion solutions and shatterproof casing to prevent any accidents and extend the unit's lifespan.

Saltwater versus Freshwater Aquariums

There are many myths surrounding freshwater and saltwater aquariums. We've no idea why though. Most freshwater aquarists know nothing about saltwater aquariums and operate/think based upon various myths that are usually inaccurate, to say the least. We're here to debunk these myths. So, without further ado, let's get right into it.

Freshwater Aquariums are Easy to Keep Compared to Saltwater Ones?

Not really but, as far as these myths go, this one is not completely misguided. This idea comes from the fact that the water conditions (pH, salinity, chloride, and more) in the oceans do not change that much at all. In other words, saltwater fish species day-to-day living conditions remain pretty constant.

Freshwater environments, on the other hand, experience noticeable cyclical changes, including but not limited to flooding and drying. These constant changes impact the waters' chemical composition and temperature. In other words, freshwater environments tend to be dynamic and inconsistent.

Because that's the case, freshwater fish species have evolved to adapt to various water conditions, whereas saltwater fishes are not as used to these changes, so even the smallest water chemistry variations can cause huge issues with them. Since you don't have to manage the conditions within this tight threshold, most people find freshwater fish species and aquariums easier to keep and maintain.

You Cannot Turn Saltwater Aquariums Into Freshwater Aquariums?

False. This time, not even remotely accurate. You can absolutely convert freshwater tanks into saltwater tanks and vice versa. Furthermore, the process is way less complicated and challenging than you'd think.

Repurposing freshwater tanks into saltwater aquariums is especially easy. All you have to do is drain the tank, rinse everything, and wipe the whole thing clean. The water you're using to rinse the aquarium ought to be warm and chlorine-free. You'll have to replace the substrate and the filters but that's about it. Of course, with saltwater tanks, you'll also need to purchase a powerhead and a protein skimmer.

Converting saltwater tanks into freshwater ones is more difficult but nothing too challenging. Basically, you have to complete the same procedure we've described above except that you'll have to be much more thorough and make sure that there are no traces of salt left on the bottom, walls, and accessories.

You'll Have No Issues Breeding Both Fish Types in Captivity

That'd great but, unfortunately, that's not the case. More often than not, even complete beginners will be able to breed freshwater fish.

Saltwater fish species are different though. These species choose to breed throughout seasonal changes. As you'd imagine, captivity means that seasonal changes are non-existent within the aquarium because they're practically impossible to recreate artificially.

Since saltwater fish species that live inside aquariums do not receive any seasonal signs persuading them to mate, expecting them to breed would not be much more than a fool's errand. That's also why saltwater fishes usually cost more than freshwater ones.

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