Top 11 Best Aquarium Thermometers 2021

We all agree that aquarium is one of the things that give the best form of entertainment. However, getting to have those small finned aquatic critters swim majestically in excitement isn’t all about introducing them to the fish tank and hoping for the best.

You have to monitor the conditions of the water closely to employ the necessary measures before it’s too late. For instance, you have to keep checking the water temperature more often for any fluctuations.

Although they are created to spend their lifetime in the waters, even the most minor changes in water temperature can cause a nightmare to these lovely beings. That’s why every aquarist needs to invest in a decent aquarium thermometer.

Like normal temperature gauges, aquarium thermometers are not all the same. They vary in construction and accuracy, and that’s why you need to only invest in a reliable model. Here are some of the market’s top options.

Top Pick
AQUANEAT 1 Pack Aquarium Thermometer, Reptile...
  • Wide application: Ideal for use in water or high moisture environment like aquarium terrarium, or vivarium; suitable for different water types such as fresh water, tap water, salty water, marine water and etc.

11 Best Aquarium Thermometers

Capetsma Digital Touch Screen Fish Tank Thermometer

Capetsma Digital Touch Screen Fish Tank Thermometer

Although some heaters have built-in thermometers, it’s wise to have a separate unit for comparison purposes. As you think about buying a separate measuring tool, consider this model from Capetsma.

This unit detects the water temperature by sticking on the outside of your glass tank. That means there are no messy wires in the water, so the fish will still have ample space for swimming and playing.

The 3.2-inch screen display is larger than that of most thermometers. That said, it’s easy to see the readings from a distance. The see-through screen means that the unit does its job without blocking your view.

The fish tank thermometer has a measurement range of between 0°C to 70°C. That’s a wider range than what you actually need. Also, the unit is accurate up to 0.1°C, so you can rely on the readings you get from it.

We love that the device has a flash function. With this feature, you can set the maximum or minimum temperature and the unit will flash when the thermometer attains either of the set levels.

Additionally, we like that you can switch between degrees Celsius and Fahrenheit easily depending on what you prefer. Lastly, this battery-powered accessory is simple to operate and works well for a wide variety of water types.

Pros:

  • You don’t have to place sensors in the water.
  • It comes with an extra battery.
  • The display is easy to read.

Cons:

  • The setup instructions can be a little confusing although you may not need them.

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RISERPO LCD Digital Aquarium Thermometer for Fish Tank

RISERPO LCD Digital Aquarium Thermometer

This piece is yet another model you can count on to help you monitor the water temperature. It will measure any temperature between -58.0 to 158.0 degrees Fahrenheit. That translates to -50.0 to 70.0 degrees Celsius.

The unit constitutes a display and a sensor probe. The screen works when on the top of the tank whereas the waterproof sensor probe has to go inside the water tank for it to measure the water temperature.

The unit has a high accuracy level of within +/- 1 degree Celsius. Hence, whatever you get from this instrument is the actual reflection of the water condition even if the built-in thermometer shows something different.

Since it works with a wide variety of aquarium tanks, we see it as one of the models that come with compatibility in mind. You can use it for freshwater, salty water, tap water, marine water, and more.

The 2 suction cups make it a breeze to mount and will keep it in the ideal place. Finally, we like that the digital thermometer can allow you to choose between degrees Fahrenheit and Celsius depending on what works best for you.

Pros:

  • It’s easy to read at a glance.
  • It has a great price.
  • The cord length is nice.

Cons:

  • Adding a backlight feature for the display would be nice.

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Zacro FBA_ZDT1-AUX-1 LCD Digital Aquarium Thermometer

Zacro FBA_ZDT1-AUX-1 LCD Digital Aquarium Thermometer

No matter the thermometer you use, it’s hard to get the exact temperature of your water tank. However, when buying, get one that comes the closest to the exact value. And yes, this instrument from Zacro is one of the models you should consider giving a shot.

The values you get from this unit are within the deviation of 1 degree. Thus, you can still rely on it to help you provide your lovely fishes with the environment they need to stay happy and healthy.

The measuring tool is straightforward to use- stick the display outside the tank using the supplied suction cups and insert the temperature probe into the tank. Long press the ‘PWR’ button to turn it on- and that’s it!

The LCD screen shows the readings using a large and readable format. Hence, you will find it quick to capture the correct values even when using the unit in areas with low lighting conditions.

The model features an LR44 battery. Hence, you can use it straight away after arrival. And with the low price tag, we see it as a perfect option for every aquarist who wants a reliable thermometer without having to pay through the nose for one.

Pros:

  • It hooks up with ease.
  • The price is hard to beat.
  • It is user-friendly.

Cons:

  • Turning it off when mounted can be a hassle.

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VIVOSUN 1-Pack LCD Digital Aquarium Thermometer

VIVOSUN 1-Pack LCD Digital Aquarium Thermometer

Keep your beautiful and expensive fish happy and more comfortable by using this aquarium thermometer to check on the temperature of the water. It’s a digital version, so there are no chances of reading it incorrectly.

The tool boasts the temperature range of -50℃ ~ +70℃. Additionally, it’s accurate to +/- 1oC no matter the corner you place the probe. Therefore, expect it to give you reliable information for use in your decision making.

The LCD shows the temperature data in a large format that you can read from afar. The size of the thermometer is also compact. Hence, it produces large readouts without itself being overly large to block your view.

Like all the preceding members of our top-notch list, the measurement unit of temperature is adjustable in this thermometer. In other words, you can have run it on either degrees Celsius or Fahrenheit depending on what you prefer.

Most thermometers come with a 60-cm cable. However, the cord of this unit is extra-long at two meters. With this length, this device will give you accurate values even when using it for the larger aquariums.

Pros:

  • It comes with 2 suction cups.
  • The cable length suits most tank sizes.
  • It’s inconspicuous.

Cons:

  • The cable length may be quite large for smaller tanks.

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LCR Hallcrest A-1005 Liquid Crystal Vertical Aquarium Thermometer

LCR Hallcrest A-1005 Liquid Crystal Vertical Aquarium Thermometer

The next aquarium thermometer on the list sticks vertically on the outside wall of the tank. It reads the temperature through the glass, so it won’t in any way take space in the tank. Thus, your fishes will have plenty of space to explore.

The accessory sticks on the wall of the water tank easily using the adhesive back. With that said, in case you want to stay away from the frustrative suction cups, this suggestion is one of the options that will hardly disappoint.

The digital readout provides clearer readings than the majority of other models. In fact, you will find it easier to read than most built-in thermometers. Furthermore, this stick-on temperature gauge remains unobtrusive unlike some members of the competition.

The aquarium thermometer is small to ensure that it doesn’t take much space on the water tank. Therefore, if you have a smaller tank and want a unit that won’t take lots of room on the wall, you won’t go wrong here.

Although it’s of high-quality, this measuring tool comes with a pocket-friendly price. That said, if you are not planning to spend heavily on an aquarium thermometer, this model has you in mind.

Unlike some models that have to rely on batteries or electricity to operate, this thermometer uses thermochromic technology. Hence, it’s easy and easy to maintain than most options.

Pros:

  • It is easy to stick.
  • It remains unobtrusive.
  • It doesn’t require batteries.

Cons:

  • It only installs vertically.

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JW Pet Company Smarttemp Thermometer Aquarium Accessory

JW Pet Company Smarttemp Thermometer Aquarium Accessory

Most people like digital thermometers because they are easier to read and provide quicker results compared to the analog versions. However, they are more often less accurate than most analog thermometers.

But how about getting a device that is easy to read and at the same time accurate? Sounds good, right? Well, that’s why we see this analog aquarium accessory as one of the top-notch products on the market.

The background of this thermometer is white while the large numbers and letters have a contrasting black color. That makes the model one of the simplest to read of all the members of the same caliber.

The unit sticks on the inside wall of the tank using an incredibly powerful external magnet. With this feature, you will find it a cinch to move the thermometer when cleaning. The magnet also means that you won’t have to deal with the annoying suction cups.

The green safe zone on the thermometer makes it easy for you to tell when the temperature is within the optimal range. We find this feature more useful, especially for the new and inexperienced aquarists.

Pros:

  • The magnetic function is a good idea.
  • The high-contrast numbers are easy to read.
  • The printed “safe zone” is a plus.

Cons:

  • Since it’s analog, it responds slowly to temperature changes.

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AUTIDEFY LCD Digital Aquarium Thermometer

AUTIDEFY LCD Digital Aquarium Thermometer

Although the price compares to that of the previous options, you are getting two thermometers in this case. With that in mind, we are safe to say that this thermometer is one of the best deals you will come across in the market.

The 2-pack makes it an ideal option to buy if you have more than one aquarium. But in case you only have one fish tank, you can use one unit in one corner and the other in another end for easy comparison.

Each unit has a temperature range of between -50 degrees and 70 degrees Celcius. However, the operating temperature range is narrower within the range of -10 degrees and 50 degrees Celsius.

The suction cups are very easy to use and will keep the two units exactly where you want them. The size of the LCD screen is perfect so that it doesn’t take much space on the wall of your aquarium.

The values of the display are also very visible and easy to read. The duo also comes with LR44 button cells to get to work straight away from the box.  While the batteries are durable, it would be better if there were replacement batteries.

Pros:

  • The 2-pack is cost-efficient.
  • The deviation of up to .1oC isn’t big.
  • The duo comes with batteries.

Cons:

  • The auto-off function after leaving it for long periods would be a nice feature.

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SunGrow Neon Tetra Thermometer with LCD Display

SunGrow Neon Tetra Thermometer

To keep your fishes more active and healthy, you have to create for them an environment similar to the one they are used to. You have to ensure that the water temperature is at the correct level at all times.

This thermometer from Sunglow is one of the options you can count on to help keep the beautiful small aquatic creatures happy and in perfect health. It comes with fantastic features and at a price that suits every pocket.

The thermometer lets you see the accurate reading of the water temperature at a glance. That said, you can take any necessary measures as soon as possible before things get out of hand.

Whether you prefer the unit temperature in degrees Celsius of degrees Fahrenheit, this accessory lets you choose the unit of display. Also, the temperature measurement range of -58° to +158°F is wide for greater reliability.

The device works by submerging the 38-inch cable inside the water. The display remains outside the tank and you can attach it to the most convenient place on the tank using the provided suction cups.

Pros:

  • It works very well.
  • You can stick the display anywhere on the aquarium.
  • It’s straightforward to use.

Cons:

  • The battery cover looks a little flimsy although it holds up well for years.

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Qguai Aquarium Thermometer

Qguai Aquarium Thermometer

Unless you have a reliable device for monitoring the water temperature of your aquarium, you face the risk of losing your adorable fishes as a result of illness brought about by fluctuations in the water temperature.

Changes in water temperature can suppress the immune system of tetras, making them more susceptible to diseases and other complications. With this unit, you will find it easy to afford your finned pets the environment they need to thrive.

The backside temperature sensor gives you the accuracy you need without the need to submerge any part of the tool inside the water. The screen has a see-through design that won’t obstruct your view once you mount it on any side of the fish tank.

Apart from telling you how cold or hot the water is, this aquarium thermometer serves as a great decoration tool. The beautiful design guarantees to keep your fish tank more visually appealing.

The device allows you to choose the minimum and maximum points within which you want to retain the temperature. The device will then let you know once the temperature rises or falls below the set levels.

Pros:

  • It is visually appealing.
  • Lets you set flashpoints.
  • The batteries last very long.

Cons:

  • It’s quite costly.

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World Digital Aquarium Thermometer

World Digital Aquarium Thermometer

No matter the species of the fish, monitoring the water temperature is the first step to giving your lovely finned beings the best life. Whether your fish prefers warmer or colder water than the others, you will appreciate that this thermometer has a wide temperature range.

The instrument provides measurements in either Fahrenheit or degrees Celsius. With the two units available for display, you can select the unit temperature that you know to interpret better or one that best matches your preference.

The minimum and maximum temperature points allow you to know any spikes in the water conditions easily. Once the temperature gets outside this range, an alarm will sound to tell you that immediate action is needed. The display unit sticks on the outside firmly whereas the probe and the cable work submerged in water.

Unlike some models that come with a short cable, the cord of this aquarium thermometer is 2 meters long. With this length, we see it long enough to allow use on larger tanks where other standard-length cables don’t offer enough length.

Like any other battery-powered unit, this gauge arrives with a battery for instant use. The AAA battery it uses lasts for a long and is easy to find a replacement once it runs out of juice.

Pros:

  • The accuracy level is fantastic.
  • It uses a standard AAA battery.
  • The alarm function is a plus.

Cons:

  • The alarm isn’t loud enough.

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AikTryee Aquarium Thermometer

AikTryee Aquarium Thermometer

The last suggestion on our top-notch list is from AikTryee, a manufacturer who has for the last two decades excelled in the market. The production of this product happens under the supervision of a highly-qualified professional team, so don’t expect it to disappoint in any way.

The accessory falls in the digital variety. Hence, it’s easier to read than the analog versions. That said, if you are looking for a thermometer for use by kids or the elderly, the AikTryee Aquarium Thermometer is one of the options you may buy.

Although very accurate, this unit claims a fraction of what other models will demand from your pocket. Surprisingly, even with the lower price, you are getting two aquarium thermometers in this package, making it one of the deals that are hardest to beat.

Each unit will need two LR44 button cells to run. And since they come in the package, you don’t need to buy them separately. Additionally, the batteries have a long lifespan of about eight months, more than you will get from other devices.

The device boasts a wide measurement range of -58 ℉ ~ +230℉ with the accuracy of ±2℉. While the accuracy level implies that it isn’t the most precise model, we still find it among the most reliable aquarium thermometers out there.

Pros:

  • The price is fantastic.
  • The duo looks nicer than most models.
  • The quality is impressive.

Cons:

  • The display may fade a little with lower temperatures.

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Frequently Asked Questions

Are Sticker Thermometers Accurate?

Stick-on thermometers are becoming very popular. They stick on the outside surface of the tank without having to submerge any part in the water. While they are reliable, they aren’t spot-on- simply because such thermometers don’t exist. However, they can get closer to within 0.5 degrees.

What Is The Most Accurate Aquarium Thermometer?

As said, it’s impossible to get a thermometer that will give the exact reading. However, choose one that gives the readings closer to the actual value. And yes, all our suggestions are high-quality and should give you dependable results.

Analog or Digital Aquarium Thermometer?

Well, each has its pros and cons. For instance, digital versions are easy to read and take less time to display fluctuations in temperature. However, they are more expensive. Analog models on the other side are normally less expensive and more accurate. Nonetheless, they take more time to show any temperature changes.

Can Fish Die If The Water Is Too Cold?

The temperature of the fish has a direct impact on metabolism. Incredibly low temperatures slow down the metabolism, making the fish more sluggish and sleepy. Warm water on the other side increases metabolism, making fish hyperactive. All these rapid fluctuations have been linked with causing stress, the major cause of death in aquarium fishes.

How Can You Tell The Temperature Of Water Without A Thermometer?

While dipping your elbow for a few seconds can give you a rough estimate of the water temperature, it’s impossible to tell the actual temperature without using a tool for the job.

Final Verdict

Although they have a simple design, aquarium thermometers play a central role in helping you maintain a stable aquatic environment for your fishes.

Now, when shopping for one, of the hurdles you have to face is choosing the right aquarium thermometer. The process can be quite overwhelming to beginners and professionals alike.

But not any more- our coverage makes the work more straightforward. Read through it all to identify your ideal option.

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