The Best Aquarium Thermometers: Most Accurate & Easy to Use

Your aquarium is likely there to provide you with comfort and entertainment. It is full of beautiful and sometimes expensive fish. Therefore, you need to make sure that the water temperature is set correctly.

To do that, you need the best aquarium thermometers. We talk about 10 different products so that you have a better idea of what is available. You are going to find that it is easier to compare them all and find out the most important facts about them.

We also include the pros and cons to make it that much simpler. You can get a quick idea and then go back and read more about the ones you like.

The 10 Best Thermometers for Your Aquariums

With so many products to consider, it’s no wonder that you might find it overwhelming. This helpful table, shown below, can provide you with quick information about each of the items on the list. That makes it easier for you to find what you want.

Pictures	Aquarium Thermometers	Types
	Zacro LCD Digital Aquarium Thermometer	Digital
	Capetsma Digital Touch Screen Fish Tank Thermometer	Digital
	JW Pet Company Smarttemp Thermometer Aquarium Accessory	Non Standing & Standing
	LCR Hallcrest A-1005 Liquid Crystal Vertical Aquarium Thermometer	Digital
	Cooper-Atkins DFP450W-0-8 Waterproof Reduced-Tip Digital Thermometer	Digital
	Marina Floating Thermometer with Suction Cup	Floating
	Windbells LCD Digital Aquarium Thermometer	Digital
	Jansamn Thermometer Sticker for Fish Tank	Stick On
	Keynice Digital Thermometer	Digital
	VIVOSUN LCD Digital Aquarium Thermometer	Digital

Aquarium Thermometer Reviews

1. Zacro LCD Digital Aquarium Thermometer

Those who want a small thermometer are going to like the one from Zacro. It has high functionality, but it doesn’t take up much space. In fact, it is only 2.17 x1.46 inches.

You can use this thermometer for various water types. These include saltwater, tap water, marine water, and freshwater.

Of course, the product is convenient because it offers both Celsius and Fahrenheit options. You also get an LR44 battery. However, you can also plug it in so that you have constant power.

The temperature is shown clearly on the LCD screen. It also goes to the tenths spot for more accuracy. Still, there can be a full degree of deviation, so make sure you account for that.

This thermometer is easy to use. All you have to do is submerge the probe into the fish tank and measure the temperature of the water. The device should not be put in water; only put the probe in the water.

Pros

• Battery operation
• Small equipment
• Suction cups included

Cons

• 1 to 1.5 degrees off at all times
• Compartment door on battery difficult to remove
• Issues with suction cup staying in place

2. Capetsma Digital Touch Screen Fish Tank Thermometer

If you’re looking for a cordless design, the Capetsma thermometer is suitable. There are no wires and probes in the water, so you don’t have to have an unsightly mess in the tank.

Instead, you use a backside temperature sensor. It sticks to the outside of the fish tank glass. Therefore, water doesn’t get inside, and there is no electronic oxidation.

You also get a large touch screen. This makes it easier to see the temperature if you’re far away. There are also large display numbers for this purpose.

The glass screen is bigger than others on the market. Therefore, nothing is going to block your view when you want to check the temperature.

This product is quite accurate within a one-degree deviation. You can also choose between Fahrenheit and Celsius. Plus, you can set the thermometer for a high and low version so that it always stays within range.

Pros

• Touchscreen capabilities
• Clear, transparent screen
• No messy wires to deal with

Cons

• Can be challenging to set to your specifications
• No instructions included
• Double-sided tape hard to remove when battery needs to be changed

3. JW Pet Company Smarttemp Thermometer Aquarium Accessory

The JW brand features an excellent, small thermometer. If you want something that is simplistic and easy to use, this is the one for you. It’s only six inches tall and about an inch wide.

You’re going to like that the background of the thermometer is white. This allows you to easily read the numbers and temperatures, which are black.

It also comes with a magnetic connection instead of a suction cup. That allows you to move it around the tank, such as when you are cleaning the glass. Plus, it continuously makes contact between the pieces, so it doesn’t disconnect with moving water.

The mount is quite unique and features a tripod design. Of course, it is relatively accurate, though there could be a two-degree deviation.

There is also a green ‘safe zone’ area directly painted onto the thermometer. This is the optimal temperature range for most applications. You can easily see it with the added color.

Pros

• Magnet security instead of suction cup
• Printed safe-zone directly on thermometer
• Easy-to-read numbers
• Simple

Cons

• Can break easily; made out of glass
• Might work slower for temperature changes
• Not highly accurate (two-degree difference)

4. LCR Hallcrest A-1005 Liquid Crystal Vertical Aquarium Thermometer

When simple is your primary goal, the product from LCR Hallcrest works well. This thermometer is a crystal-clear one that is designed to move around. It’s very accurate, as far as such devices go.

Still, there could be some variance in readings. This isn’t a significant concern for most people. Just make sure to adhere it to the tank as far away from the heater as you can.

It looks a little odd right out of the package, as there are multiple colors. Check the green box to read the temperature (which is current). The brown box indicates one degree higher, and the blue box is a degree lower.

There could also be a slight mixing of colors, depending on the actual temperature of your aquarium. However, it is intuitive and easy to figure out once you know the trick and how to read it accurately.

Pros

• Highly accurate
• Easy to read
• Suction power for adhesion

Cons

• Could be up to one degree off, which seems normal
• Hard to read without a flashlight/direct light
• Must be close to thermometer to see the numbers

5. Cooper-Atkins DFP450W-0-8 Waterproof Reduced-Tip Digital Thermometer

For people who want to check the temperature of their aquarium, the Cooper-Atkins brand might work. It is not designed for tanks, though. However, the thermometer tip is waterproof.

The goal here is to remove the thermometer from the sleeve and touch it to the water. Get your reading, and then remove the probe and put it back in the protector.

There is no way to affix the thermometer to the tank indefinitely. You must insert the probe into the water and back out periodically to test the temperature.

Of course, you can use this thermometer for other purposes. Just make sure that you clean the probe before inserting it into food you plan to consume.

Temperature ranges go from -40 degrees up to 450 degrees Fahrenheit. It does not measure in Celsius. However, it is highly accurate and can test temps for many aquarium needs, including freshwater, saltwater, and regular tap water for your benefit.

Pros

• Easy to read
• Quite accurate
• Easy to use

Cons

• Large head; issues with balance
• Not designed for aquariums specifically
• Sleeve wears out quickly

6. Marina Floating Thermometer with Suction Cup

If you’re interested in a traditional style of the thermometer, the Marina brand has what you need. The design is simple yet effective. Of course, the liquid pools in the bottom and raises to indicate the temperature.

This product features a green space, which indicates the ideal temperature for your aquarium. Therefore, you do not have to stare at the thermometer to try and determine where the line is. As long as it is in the green zone, you are safe, and so are your fish.

It’s a floating thermometer, but it has suction cups. You adhere the cup to the side of the tank. That means the thermometer can move around, but it isn’t going to fall out of the suction cup holder.

Primarily, this product is designed for fresh- and saltwater use. The safety zone indicator works for many tropical fish. However, yours may need a different ideal temperature.

Pros

• Quite accurate
• Fits on the side of the tank
• Features a ‘safe zone’

Cons

• Damage to acrylic tanks possible with suction cup
• Strong chemical smell upon opening package
• Can be hard to get the reading with the red gauge and the green safe zone

7. Windbells LCD Digital Aquarium Thermometer

People who want a digital thermometer for their aquariums are going to like the Windbells brand. It is easy to read, but it features a compact design. Still, the LCD is large enough to glance at it and see the numbers.

You can choose to view the temperature in Fahrenheit or Celsius. Therefore, it is optimal for a variety of fish tanks and needs. Plus, the range goes from -50 to over 70 degrees Celsius.

Of course, you want it to be precise. This thermometer is accurate to within 0.1 degrees. Therefore, you aren’t going to wonder if it works properly.

It does require some assembly, which is easy to master. Attach the suction cups to the LCD and the end of the probe. There are easy-to-use sucker buckles to make this easy to put on the display unit, and the one on the probe is already affixed.

Pros

• LCD display
• Fahrenheit and Celsius readings
• Highly accurate to within 0.1 degree

Cons

• Instructions not easy to understand
• Issues with suction cups not adhering to the tank
• Uses battery power to function

8. Jansamn Thermometer Sticker for Fish Tank

Those who want something a bit different might like the thermometer sticker from Jansamn. All you have to do is peel off the backing and stick it to your aquarium. Make sure to put it on the outside of the tank and not on the inside, as water can remove the adhesive.

The strip works with both Fahrenheit and Celsius temperature ranges. You are going to like that it goes from 39 to 97 degrees Fahrenheit and 4 to 36 degrees Celsius. Of course, the Fahrenheit numbers are a bit larger than the Celsius ones, which can pose a problem if you prefer readings in Celsius.

This product works by coloring the current temperature. Since it lays on a black background, it should be easy to see the change. However, you may want to use a flashlight or the light on your phone to make it a bit easier to read.

Pros

• Easy-to-read numbers
• Suitable for constant temperature monitoring
• Small profile

Cons

• Must use light source to read
• Paper from peeling can stick
• Hard to understand how to use at first

9. Keynice Digital Thermometer

Many people like a digital thermometer, but the one from Keynice goes above and beyond. When you plug it in, you first see that it shows the temperature. However, there is also a graphical display to indicate that it is either low, normal, or high.

This works well for people who often glance over at the thermometer to get a general idea of what is going on. Keep in mind that this product is designed for many uses. You can check temperatures in pet habitats, cars, computer towers, and aquariums.

Temperatures are displayed in either Fahrenheit or Celsius with a one-degree deviation for accuracy. The unique design allows it to be surface- or flush-mounted. You are going to need a mounting hole of about 1.83×1.08 inches.

Instead of a battery to power the device, you get a USB power source. This is ideal for many applications, but you do need the right equipment, especially if you plan to use it for an aquarium.

Pros

• Graphical display
• Features Fahrenheit and Celsius displays
• Powered by USB (no batteries)

Cons

• Can be hard to read, depending on your angle to it
• Temp probe could be longer
• No dimmer option; display very bright

10. VIVOSUN LCD Digital Aquarium Thermometer

When you need an accurate thermometer, the VIVOSUN brand has you covered. It has a temperature range of -50 to 70 degrees Celsius or -58 to 158 degrees Fahrenheit. Plus, it is accurate to within a degree (over or under).

It doesn’t matter what corner you put the probe in, either. The temperature is always accurate and displayed correctly. Of course, it also features an LCD readout, which is easy to read, regardless of where you stand.

If you want to adjust between Celsius and Fahrenheit, you just long-press on the power button. You may also slide the bar from “F” to “C” to make these changes.

There are two suction cups, and one is attached to the probe. The other is put on the thermometer so that you can display it on the outside of the tank. Of course, you also get a long cable, which fits bigger fish tanks.

Pros

• Waterproof probe
• Large LCD screen
• Use for a variety of applications

Cons

• Issues with suction cups adhering to tanks
• Sits loose or angled in the suction cup
• Can have display issues

How to Use a Digital Aquarium Thermometer?

A thermometer is generally used to measure the temperature of your aquarium water. Some thermometers allow you to constantly monitor the temperature and alert you whenever the temperature rises or drops outside your chosen range or setting.

If you have an exceptionally large tank, you can easily make use of several thermometers to monitor different areas of the aquarium. Simply ensure that the display is easy to view in order for you to be able to know the temperature immediately.

Where to Put a Stick-On Thermometer in an Aquarium?

Stick-on thermometers are most widely used in freshwater aquariums. They are often offered as a feature in the latest aquarium package. When making use of LCD thermometers, there are a few tips that should be followed.

1. Do not put them in an area where they will come in contact with direct sunlight, or any area close to a cooling or heating vent. Aquariums shouldn’t be put in areas such as these anyway.

2. Do not put the thermometer below ground level, as this will influence the accuracy of the reading.

3. Finally, the thermometer does provide the best reading when it is viewed straight on, therefore place it properly. If you have any need to twist your body in order to see the thermometer display, it is not in an ideal area.

How to Read an Aquarium Thermometer Sticker/ Strip?

Some amphibians and fish are extremely sensitive to changes in temperature and will suffer or even die if the water is excessively hot, excessively cold, or fluctuates. An adhesive strip thermometer indicates the temperature of the water by showing three different colors.

Since each color shows different temperature, any individual who hasn’t used a temperature strip before may not be able to get an accurate reading. One-color is the correct temperature, while the others show a temperature that is either cooler or hotter than the correct temperature.

Stage 1

Clean the exterior of the aquarium using aquarium-safe glass cleaner, or simply water. Try not to make use of standard glass cleaners or soaps, as the chemicals used in those products may contaminate your water. Thoroughly dry the aquarium with a towel. Make sure that the glass is totally dry.

Stage 2

Peel the plastic backing off the strip and place the strip on the tank exterior, beneath the uppermost water level. Make sure that the strip is smooth and free of bumps.

Stage 3

Check the strip after 15 to 30 minutes. Three colors will be observed, with each having a number. Green shows a correct temperature, while violet or blue shows a temperature that is beneath the accurate temperature. The tan or red color shows temperature over the accurate temperature.

Types of Aquarium Thermometers

There are different types of aquarium thermometers. It is very essential for you to know the various types that are available in order to be able to pick the right one for your tank temperature modification needs. The most widely recognized kinds of aquarium thermometers are:

1. Digital Aquarium Thermometer

This kind of aquarium thermometer is well known to be the priciest of all, particularly when you buy the best digital thermometer for your aquarium. However, some dependable digital thermometers are really very cheap, despite the fact that they are exceptionally accurate. They aren’t influenced by the ambient temperature of the room.

The setup of the device is normally a probe matched with a digital display that is simple to read. Sometimes, the reading of the temperature is in both °F and °C. Generally, there is a wire that links them to one another, but some always come with a wireless connection. A lot of these devices are powered by batteries, yet some can be connected to an electrical plug.

Sometimes, the probe is placed in the fish tank to constantly monitor the temperature. It might even come with an alarm feature that will notify you when the temperature leaves your chosen range. The thermometer is very robust and is just unbreakable. In case you are searching for the best thermometer for your freshwater aquarium, you will need to check out this category.

2. Floating or Standing Aquarium Thermometer

With this type of aquarium thermometer, you will need to submerge the entire thing. This isn’t digital, so you might experience difficulty reading the little print scale. To tackle this issue, some makers have a wide variety of colors for the protected zone, so you will know immediately when the temperature drops out of your chosen range. However, when you have a huge tank, you might need to consider utilizing a lot of these aquarium thermometers on either side of the tank.

One major concern here is that a large number of these aquarium thermometers are built with glass. That makes the devices to be considerably more fragile compared to the other kinds of thermometers.

However, some models are built with stainless steel while others are built with plastic. Many make use of suction cups to remain set up. Some are highly magnetic, which implies that you can sustain it using a magnet outside. Other models are flowing freely in the water but you can likewise get standing models weighted at the base.

These devices are very cheap. But you may not find some features like LCD readings or even alerts. It is likewise not as accurate as of the first type of aquarium.

3. Stick-On Aquarium Thermometer

In some cases, these are known as LCD thermometers since they have a kind of LCD display. Some makers have even attempted calling them digital thermometers, however, they are not similar to the real digital thermometers discussed earlier in this buying guide article. Ensure you aren’t getting an ordinary LCD thermometer when it is a digital one you require.

The stick-on thermometers are positioned on the outside part of the aquarium, and that makes the temperature reading less dependable. Their readings can be influenced by the room’s air temperature. Also, it is really bad if they are positioned in direct sunlight, near vents, heaters, and other items or locations that can influence the temperature.

You likewise won’t want to place it underneath the rock level, as it will not be as accurate at that point. The LCD is likewise best displayed straight on, so you need to position it where it can be viewed easily.

Conclusion

One of the essential tools on the mother earth for both tank owners and fish is the Aquarium thermometers since it tells the temperature of the water. This is simply because you generally need to keep the temperature of the water at a reasonable level for the fish. There are three essential kinds to pick stick-on, floating/standing, and digital.

However, the most preferred kinds are the digital aquarium thermometers. The digital thermometers reviewed in this are almost the same, and they are quite a great choice. But if we should pick one, it would be the Zacro Digital Aquarium Thermometer. The LCD display is somewhat better compared to the other options reviewed here. In addition to the fact that it’s the number top-rated seller makes it a great choice.

See also:

The Best Aquarium Heaters That Work & Safe for Your Fish