Best Aquarium Thermometer To Purchase In 2022

You need specific equipment to monitor your fish correctly as a fish owner. And one such piece of equipment is an aquarium thermometer. As you know, an Aquarium thermometer is a small piece of equipment used to maintain the water temperature of your fish and adjust it accordingly. 

Every living thing has a temperature range that it can survive in. For fish, corals, or plants, this temperature usually varies. Temperature changes also vary based on the season and weather. But you must keep an eye on the water temperature of your fish since a change might result in disaster. 

Like every aquarium tool, there are several aquarium thermometers you can buy. So in such cases, choosing the most suitable thermometer for your needs can be challenging. 

Read on to find 8 of the best and budget-friendly thermometers you consider purchasing. Additionally, you will find help in choosing the suitable aquarium thermometer and the benefits they have for you. 

Let’s begin.

Things To Consider When Choosing An Aquarium Thermometer

Aquarium Thermometer
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With the need to choose the right water temperature being so important, you must know things you should consider to get the best fit. These thermometers are an excellent way to check your aquarium temperature and ensure your fish are doing well. 

With various aquarium thermometers to choose from in the market, it can be confusing to pick the best fit for you. So, below are some things you should consider. 

1. Accuracy 

One of the essential factors of an aquarium thermometer that you should consider is its accuracy. There will be no point in monitoring the temperature of the water if you are not sure of getting the right or accurate reading. 

Most digital thermometers tend to be more precise. But unfortunately, they usually reduce the most significant variable in thermometer accuracy: the person reading the result. 

For mercury-in-glass or a traditional thermometer, you can easily misread it. But with LCD or digital readout, this is not a problem. 

2. Type of thermometer

There are different kinds of aquarium thermometers you can purchase. They all produce varying accuracy, so choose the one that suits your fish type and tank. 

Also, when choosing a thermometer, choose one that fits your budget and your aquarium needs. There are several types of thermometers. 

They are floating/standing, stick-on, fixed probe, and digital thermometer. Digital thermometers are accurate when standing, easy to use, and best suit larger tanks.  Let’s take a look at them.

  • Digital thermometer

Digital Aquarium thermometers have digital display units kept outside the tank while the probe is submerged in the water. Digital thermometers are either in wireless models or wire models. 

They are well known for their highly accurate readings, and the thermometer probe is usually submerged in the water. And most digital thermometers generally have an alarm system that comes on when the temperature decreases and exceeds the intimate one.

Reading the temperature of a digital thermometer is quite simple and easy since they are either in Fahrenheit or Centigrade scale. Its only drawback is that they are generally more expensive than other thermometers. 

  • Floating/standing thermometers

The floating or standing thermometers are analog thermometers. These types must be fully submerged inside the water to get an accurate result. They are usually placed with a suction cup to stay put. 

These thermometers provide precise results since they are generally submerged inside the water. So, the outside temperature doesn’t have any means of affecting the result provided. 

A disadvantage is these thermometers are not easy to read. They also have no alarm system in them. They can be very fragile since they are made from glass. 

It can easily break inside the tank, which can create a mess. Also, sometimes, the suction cups are not good enough and lose their performance with time. 

  • Stick on/LCD thermometers

The LCD or stick-on thermometers are inexpensive, and the excellent features are that they seldom break. They usually have a thin LCD strip that is placed outside the tank. These thermometers are pretty easy to read because of their LCD.

Its downside is with these thermometers; the sticks hang outside the wall of the tank. Thus, they sometimes don’t provide the right results since the temperature outside usually affects it. So, ensure the stick is not placed under heating devices or direct sunlight since this might affect the results.

  • Fixed probe

They are also called instant-read thermometers. They can be easily identified via the meter attached to the sensor probe. All you need to do is dip the probe into your aquarium. 

Then, you will find the temperature shown on the digital display in seconds. This is quite similar to pen-style thermometers moms use for checking roast. This type of thermometer is quite small and utilizes little space. 

This keeps them hidden from view in your aquarium until you next need to check your tank’s temperature. The downside is that this temperature must be held by hand. If you don’t hold it by hand, it will fall into the bottom of your aquarium.

3. The temperature range

You must pay attention to the temperature range of a thermometer. This goes without saying that you need a thermometer suitable for the temperature range you want to monitor. A small range would give you less flexibility. If your fish are best suited for tropical weather, purchase a thermometer with an extensive temperature range. 

Conversely, if your fish is best suited to cold temperatures, buy a thermometer that can range below 20 degrees centigrade. For most aquariums, a range of 10 degrees C (50 degrees F) and 40 degrees C (104 degrees F) is sufficient.

4. Ease of usage/user friendliness

It is not an easy feat to maintain an aquarium. In addition, you also need to take care of the several apparatus you use. So, with these tasks, you shouldn’t be bothered about a thermometer with a complicated setup. 

Therefore, when deciding to purchase a thermometer, choose one that is easy to install and also easy to use. The only job of an aquarium thermometer is to tell you what the temperature of our tank water is. Sounds simple right? So, they shouldn’t be very complicated to use or even set up.

You can place the best thermometers in your tank without being bothered about anything. But, digital thermometers usually need additional installation steps and maintenance procedures like battery changes. But, you can also decide to go for those without complicated settings or that are extremely fancy. 

You should also consider the type of thermometer mentioned above. Ease of use is one of the major deciding factors when choosing a thermometer over another. This does not mean that the simplest is the best, but it is a suggestion that you consider how easy it is to use as a part of your overall consideration of the tools.

5. Safety for your fish

It would be best if you chose a safe thermometer for your fish. It shouldn’t have chemical or toxic leaching. If it is made of glass, it should be shatter-proof. 

6. Durability

Aquarium thermometers might not be overly expensive, but you should ensure you get one that is well built and can last.

For example, you shouldn’t go for a poorly made mercury-in-glass thermometer which will slip from your tank’s side and break, resulting in a mercury leak in your tank. Similarly, buying a cheap digital thermometer with an LCD that fails quickly or doesn’t work correctly is also useless to you.

7. Temperature readability/display

Irrespective of how good a thermometer is, if you cannot read the display, then it is not worth buying for use. So get a thermometer with a clear display so you can easily read the readings. 

When the thermometer is submerged in the water, it can be hard to read the number. So, ensure you get a thermometer with good display features that you can read at a distance.

Thermometers with more significant probes and LCD usually serve better for readability. Some are pretty easy to read, while others might require the use of a magnifying glass or flashlight to see the number appropriately. 

So the key point here is to get a good thermometer and the right one for your aquarium setup. When you consider the above factors, you can be sure of choosing the right products that can ideally help you maintain your tank’s temperature.

Benefits of Using An Aquarium Thermometer

Having an accurate thermometer is very crucial. They can help you check your fish’s temperature at least once daily. Doing this means you can check the temperature early when changing the water or feeding your fish. 

In addition, a reliable thermometer will prevent any disaster that can happen to your tank. There are several reasons why you should use a thermometer. Aquarium thermometers, whether digital or other types, come with several benefits that make them a great choice. 

Below are some of its benefits:

  • Gives your fish a stable water temperature 

Fishes and invertebrates need a stable water temperature. Thus it would be best if you sustained homeostasis. Stable water temperature can make all the difference between aquariums and a healthy tank. Conversely, water temperature fluctuations can stress your aquarium’s inhabitants.

The result would lead to a vulnerability of your fish to diseases such as fin rot. When these temperature fluctuations are not appropriately and promptly addressed, they can kill all inhabitants of your tank. So, a daily check of the water temperature in your tanks with a thermometer would enable you to find these inconsistencies. 

When added with a quality heater, you can prevent temperature changes in your tank. It might seem attractive to purchase the cheapest option you can find when choosing an aquarium heater, but it is common for heaters to break. And this might lead to you losing all your fish. 

So, when making water changes, you must match the temperature between the water you are replacing and the new water. And this is where the need for a thermometer comes into play to ensure the temperatures match.

  • Helps with proper measurement when changing tank water

Broken heaters and similar issues are quite dangerous. So, using an accurate thermometer and matching the old water with the new water can help you sustain a stable temperature to prevent unexpected incidents.

When water rapidly becomes cold or cold, it can kill your fish. However, having a working and accurate thermometer would ensure you can check the temperature changes early. 

  • Proper alarm for notification of temperature changes

New thermometers that are available for purchase now have alarm systems. These alarm systems can warn you when temperature changes (rise and fall). 

When you use a thermometer, you can confirm that your fish swims in the water at the best suitable temperature. With it, you will be alerted of temperature changes and fluctuations, so you can make changes to deal with the situation. 

8 Best Aquarium Thermometer You Can Get From Amazon

  1. JW Aquarium SmartTemp Thermometer
  2. Marina Deluxe Floating Thermometer With Suction Cup
  3. Fluval 2-in-1 Digital Aquarium Thermometer
  4. Zacro LCD Digital Aquarium Thermometer
  5. AQUANEAT Aquarium Digital Thermometer
  6. LCR Hallcrest A-1005 Vertical Aquarium Thermometer
  7. Capetsuma Digital Touch Screen Aquarium Thermometer
  8. VIVOSUN 1-Pack LCD Digital Aquarium Thermometer

Our choice

  1. BEST OVERALL: JW Aquarium SmartTemp Thermometer
  2. RUNNER UP: Marina Deluxe Floating Thermometer With Suction Cup
  3. THE BUDGET DEAL: Zacro LCD Digital Aquarium Thermometer 
  4. BUDGET ALTERNATIVE: AQUANEAT Aquarium Digital Thermometer

1. JW Aquarium SmartTemp Thermometer

If you want to purchase the best aquarium thermometer, you should consider the SmartTemp Aquarium Thermometer from JW Pet Company. This in-tank thermometer is created to securely fasten to the side of your tank through the aid of a strong magnet.

This means that your fish or water movement won’t be able to knock it off accidentally. In addition, it is very well built with a clear and easy-to-read display, including safe zones marked in green for easy usage.

It has a simple mercury-in-glass design, so you don’t need to worry about changing batteries or calibrating the thermometer. It is always on and is consistently accurate. Little wonder why it comes on top.

Product Details:

  • Material – ABS, and Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
JW Aquarium SmartTemp Thermometer
  • We are proud to introduce the NEW SmartTemp Thermometer
  • This unique design combines a thermometer with a magnet
  • The Thermometer goes on the inside of the tank and the magnet goes on the outside to hold the SmartTemp firmly in place, no suction cups needed

2. Marina Deluxe Floating Thermometer With Suction Cup

The Marina Deluxe Floating Thermometer is unique in that it has a smaller size than other products you can find on the market. Therefore, it can easily fit your tank. You should go for this product if you have a small tank size or few fish in your aquarium. 

In addition, this product has suction cups installed at the top, which makes it easy to read the water temperature. The thermometer floats around in your aquarium. So, it can easily read the temperature of all corners separately. 

A marked safety zone shows the limit, after which you must bring down the temperature. The thermometer is about 4.25 inches, and it is transparent, which makes it easy to read. 

Product Details:

  • Material – ABS, and Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
Marina Deluxe Floating Thermometer
  • Easy-to-read floating thermometer
  • Includes a safety zone indicator
  • Equipped with suction cups
  • Ensures your aquarium is at a proper temperature
  • Temperature range of 30 to 120 degrees Fahrenheit

3. Fluval 2-in-1 Digital Aquarium Thermometer

Fluval makes excellent aquarium tools, including thermometers, fish tanks, filtration systems, and pumps. The Fluval 2-in-1 Digital Aquarium is another thermometer that doesn’t disappoint its users by providing accurate readings ranging from 68o to 80o Fahrenheit. It does this through a clear and huge LCD which you can easily read from a distance. 

Another handy feature is its capability of provisioning reading for both tank water and ambient room temperature. This thermometer is fixed outside your aquarium glass, and you can use it in freshwater and saltwater tanks. You also get a product warranty which is quite reassuring. 

Product Details:

  • Material – ABS, and Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
Fluval 2-in-1 Digital Aquarium Thermometer
  • 2-in-1: Measures water & room temperature accurately within 10C/20 F
  • No probes or messy wires
  • Large LCD display simultaneously shows aquarium and ambient room temperatures
  • Thermometer for use in fresh and saltwater aquariums

4. Zacro LCD Digital Aquarium Thermometer 

At its first appearance, the Zacro LCD  Digital Aquarium Thermometer is of a similar design to the Marina device, which we mentioned above. Both thermometers share features like a wide temperature range, sizable digital readout in Celcius and Fahrenheit, and auction cup mounter probe. 

But, several detectable differences make it come lower on this list. One of such apparent differences is that it is not as accurate as the Marina device and only has one-degree accuracy. Another noticeable difference is its price since this equipment is less expensive.

Product Details:

  • Material – ABS, and Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
Zacro LCD Digital Aquarium Thermometer Fish Tank Water Terrarium Temperature
  • Submerge probe into fish tank to measure water temperature (Submerge probe only, do not submerge thermometer in water)
  • Easy to apply suction cup and easy to read LCD screen; Temperature readings to within 0.1 degree
  • Large, easy to read LCD display. Compact design for discrete use
  • Temperature range -50 degree Celsius~ + 70 degree Celsius; Operating temperature -10degree Celsius~ +50degree Celsius
  • Powered by one LR44 button cell (included)

5. AQUANEAT Aquarium Digital Thermometer

The AQUANEAT Aquarium Digital Thermometer is similar to the Zacro device mentioned above. The significant difference is the slightly larger suction cup that holds the probe in place. 

However, it has the same features, including a choice of Celcius and Fahrenheit, a large and easy-to-read digital display, and a wide operating temperature range. 

Another considerable difference is its wide application. You can use it in high moisture environments like vivariums, terrariums, and aquariums. It is also suitable for several types like marine, salty, tap, and freshwater.

Product Details:

  • Material – ABS, and Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
AQUANEAT 1 Pack Aquarium Thermometer
  • 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.
  • Easy to read: Comes with a large LCD display that is easy to read clearly
  • Easy to setup: Submerge probe with suction cup can easily be set in water (Submerge probe only, do not submerge thermometer in water) ; Press ”PWR” for 3 seconds to power off
  • Free extra LR44: 2 PCS LR44 button cell for each thermometer (one for operation, one for spare)
  • Wide temperature range: Measure -58°F to +158°F (-50°C to +70°C) with accuracy +/- 1°C

6. LCR Hallcrest A-1005 Vertical Aquarium Thermometer

The LCR Hallcrest A-1005 Vertical Aquarium Thermometer is a popular stick-on LCD design thermometer mounted outside an aquarium. Though it isn’t submerged inside the water, it is pretty accurate. 

The only exceptions are thick glass-walled aquariums or if the temperature outside the tank is significantly colder than the temperature in the water.

In this case, the temperature might be off by a couple of degrees. However, the product is very easy to install and use and reasonably inexpensive. 

Product Details:

  • Material – ABS, and Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
LCR Hallcrest A-1005 Thermometer
  • Easy To Read
  • Mounts Vertically On The Outside Of Your Aquarium
  • Easily Movable
  • Country of Origin: CHINA

7. Capetsuma Digital Touch Screen Aquarium Thermometer

This thermometer measures the water temperature from the outside of the tank. It doesn’t have probes or wires that must contact the water. It just needs to be placed outside the glass. It is pretty easy to set up, with a sticky pad on its back which you need to peel off and stick to your tank’s side.

However, its downside is that it is not as accurate as the others and can’t be repositioned after it has been placed on the glass. 

On the other hand, it has a large touch screen, making it easier to operate, switch between Fahrenheit and Celsius, and read the temperature from far away. It reads temperature ranges from 0°C to 70°C / 32°F – 158°F. 

Product Details:

  • Material – ABS, and Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
Capetsuma Digital Touch Screen Aquarium Thermometer
  • 🎈 No Probes or Messy Wires in water : backside temperature sensor stick on the outside glass of the fish tank prevent water infiltration and electronic Oxidation, Classic Red+Black compact design with Large Crystal Touch Screen makes it easier to read the temperature far away, stands out among other Fish Tank thermometers.
  • 🎈 Large numbers on 3.2″ Large Transparent Screen : 3.2″ large glass screen is larger than most of the thermometers, large temperature display on transparent screen, will not block your view.
  • 🎈 Accurate Display : With an accurate temperature sensor stick on the surface of the fish tank, this Digital aquarium thermometer will display accurate temperature for fish tank, reading from 0°C to 70°C / 32°F – 158°F, accurate to 0.1°

8. VIVOSUN 1-Pack LCD Digital Aquarium Thermometer

This thermometer is quite similar in design to the Zacro model reviewed above. It works similarly with a probe attached to the tank and then connected to the central unit through a cable. 

Moreover, it also has a large digital display that is clear and easy to read. In addition, you can switch the display to either Celsius or Fahrenheit. Another benefit is that you can easily install it with the needed battery. 

Product Details:

  • Material – Plastic
  • Wattage – 2.6 W
  • Voltage – 3.7 V
  • LED Color – White
VIVOSUN 1-Pack LCD Digital Aquarium Thermometer
  • High Accuracy: Temperature Range: -50℃ ~ +70℃ (-58 °F ~ +158 °F); This aquarium thermometer is accurate to +/- 1℃, no matter whether the probe is placed in any corner of this fish tank, an accurate temperature will be displayed
  • LCD Display: Comes with a large LCD display that is easy to read clearly and accurately
  • Adjustable Unit Tempature: Easy to adjust the temp between Fahrenheit and Celsius displays; Long-press the power button to adjust the unit display


So here you have it, our top 8 picks for the best aquarium thermometers on Amazon that you can consider if you need a thermometer. Above, we indicated the advantages of each thermometer and our verdicts to help you choose the one that suits your needs.

Ensure you follow the factors mentioned above to get the best thermometer. We hope this article helps you purchase the aquarium thermometer you are looking for so your fishes can enjoy the right temperature. Also, if you have questions or require help choosing a suitable thermometer, don’t hesitate to contact us.

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