10 Best Aquarium Thermometers in 2019 [Reviews & Guide]

Aquarium Thermometer

The water temperature in the aquarium is very important to monitor to keep your fish fresh and healthy. Some fish needs warmer water and some fish needs cold water so there are various types of fish to be protected in your fish water aquarium. You must choose the simplest thermometer which can give you the convenience to adjust the thermometer and monitor the temperature inside the aquarium.

A well-designed thermometer must be capable of submerging in the water or it must have a probe to attach to the cable, it is used for getting an accurate water temperature. The mercury and color changing crystal thermometers also work efficiently so the digital thermometer is not needed.

Most of the fishes can live only in specific water temperature so monitoring the readings is very important to the health and happiness of your fish. Some thermometers come with an alert feature which can help you to set off an alarm whenever the water temperature changes from the normal temperature. You must have a clear idea before picking the thermometer, it will be designed with lead and mercury substances which can harm your fish when it breaks so choose the best aquarium thermometer to keep your fish alive for a long time.

Marina Floating Thermometer with Suction Cup

Marina Floating Thermometer

The Marina Floating Thermometer with Suction Cup is accurate and it is easy to read, you can just simply float in the water and get an exact reading. It is very simple and easy to use a thermometer, you can float it in a vertical position and it comes with a suction cup so you may easily attach it to the walls of the aquarium. It can be able to measure 4.25 inches tall by floating it on the wall inside the tank along with the suction cup.

The temperature readings can be either in Celsius or Fahrenheit with a click of a single button you can easily switch between Fahrenheit and Celsius, and also has a safe zone indicator so you can easily identify whether it goes outside the safe temperature. It is very simple to use this aquarium thermometer because it does not require any batteries but gives an exact temperature reading 100 percent of the time. It has the potential to protect the fish from unsafe temperature so that it can stay for a long time without any damages.

The Marina Floating thermometer does not use LCD display to measure but it makes use of the time-tested method of using mercury to measure the accurate readings. The overall design of this thermometer can be sleek and compact it is well designed with a lightweight material, so you can easily carry it. This thermometer comes with a suction cup so it is easy for you to stick it inside your aquarium wall.

HDE Digital Aquarium Thermometer

HDE Digital Aquarium Thermometer

It is very simple to track the water temperature with this HDE Digital Aquarium thermometer; it is very large and has easy-to-read LCD display screen. It gives a more versatile temperature range between -50 and +70 degree Celsius. This HDE Thermometer will be very convenient for you to monitor the temperature of water in the fish tank. It can be stuck easily on the walls of the aquarium glass to offer an accurate reading both in Fahrenheit and Celsius.

The suction cups are fixed at the outside of the tank and the temperature gauge is kept inside the tank for attaining the perfect reading. It is constructed with two main components one is a sensor and the other is display, the end portion is designed with a suction cup which is attached to give a secure fit to the aquarium.

If you submerge the sensor inside the water then it is possible to get an exact temperature. This thermometer has a built-in LR44 battery so you can be ready to measure the reading, if you need to switch on the thermometer then simply press the “on” button, now you can be able to measure the aquarium’s temperature and check the fish health. It is also possible to switch easily between Celsius and Fahrenheit.

Zacro Digital Aquarium Thermometer

Zacro Digital Aquarium Thermometer

The Zacro Digital Aquarium thermometer is designed with an LCD display so it will be easy to read, it also shows the temperature either in Fahrenheit or Celsius. It is powered up with LR44 button battery cell so it is highly durable and can last for a long time; it can be easily replaced by another battery. This thermometer can have an extraordinary temperature range; the normal reading can be -50 degree Celsius to +70 degree Celsius it is one of the most versatile thermometers.

It adds more convenience to you by having the suction cup so you can easily stick the thermometer just at the exterior part of your fish tank. It has a compact design; the sensor should be submerged into the water to gauge the exact temperature. When you plan to buy a fish tank it is very important to see whether the fish are staying comfortable and have the exact temperature.

The Zacro LCD digital Aquarium thermometer is the best for monitoring the accurate reading. It produces an absolute reading at both salt and freshwater tanks. It is possible to float the thermometer into the fish tank in a vertical position so that you may easily get the aquarium’s temperature perfectly. It is not necessary to submerge the aquarium thermometer into the tank, just place the probe inside it. This equipment is not too heavy; it is designed in a smooth and conservative manner.

American Thermal Instruments Aquarium Thermometer

American Thermal Instruments Aquarium Thermometer

It is one of the best aquarium thermometers which offer an accurate reading; it is very compact and easy to carry aquarium thermometer which uses many varieties of touching colors. It gives a lot of conveniences to read the temperature because it is properly designed, this is very easy to install just peel off the film on the back side of it and gently stick it to the inside of your aquarium.

The thermometer should be completely submerged for getting an efficient reading, it doesn’t use LCD display it simply uses the color changing crystals to indicate the temperature range. The color of the crystals varies depending upon the temperature inside the tank, it is mandatory to compare the color with a color chart to attain accurate reading.

You must choose the place to fix the thermometer whether to fix below the waterline or outside of the aquarium. It weighs about 0.3 ounces and it is possible to fix the thermometer horizontally, the back portion of the thermometer helps to sense the temperature inside the aquarium through the glass, the reading is shown in a digital display of the temperature. It is the best idea to use adhesive to peel off the film, the liquid crystals can be used to gently remove it and then place in a proper location.

Lifegard Aquatics Digital Temp Alert

Lifegard Aquatics Digital Temp Alert

The Lifegard Aquatics thermometer has a large display thermometer for both freshwater and marine aquariums; it also has the ability to measure room temperature as well as the water temperature inside the aquarium. It has a probe that measures the aquarium temperature and the internal thermometer measures the room temperature.

The Digital Temp Alert is designed with a programmable alarm which alerts you when the temperature is above or below the expected range. It does not use the LCD thermometer to measure the readings; it just uses the normal measuring tool to take the air temperature. This thermometer can be used in saltwater and freshwater aquariums.

The suction cup is designed to stick it on the side of any aquarium; it has easy to read digital display so you can note the temperature without any mistakes. It comes with a simple user interface so it will be very convenient to use even for the beginners. The suction cup is attached to the in-tank probe so you can fix it to the aquarium glass easily, there are four levels of temperatures if a red light indicates then the temperature is out of range.

TOOGOO Digital LCD Fish Aquarium Thermometer

TOOGOO Digital Aquarium Thermometer

The TOOGOO Digital Aquarium Thermometer is very easy to use and offers a wide temperature range; it has a compact design and does not require much space. It comes with a high-quality LCD display which helps you to mark the temperature accurately; it is not too heavy just 3.5 ounces so you may not feel very tough to install it using the suction base.

It is powered up with DC 1.5V LR44 button battery so it can last for a long time. You can get accurate readings using this thermometer either in Fahrenheit or Celsius; it is highly durable so it will not break when you drop it accidentally. To save the battery life just power off the thermometer display and turn on when it is needed to see the temperature.

The portable digital LCD thermometer can measure the temperature range from -10 degree Celsius to +70 degree Celsius. This device is mounted with a high-quality suction base to ensure that the thermometer does not fall inside the fish tank and end up breaking. There is a sensor attached to the aquarium thermometer so it is not needed to fix the device directly back to the fish tank. You can charge it with a powerful battery which also works when plugged.

Pet Magasin Digital Thermometer

Pet Magasin Digital Thermometer

This is very unique digital thermometer but very useful, it also acts like a hygrometer because it is capable of reading the humidity in the air. It is very compact and an affordable digital thermometer which allows you to monitor the exact temperature. It is designed with an elegant and convenient LCD display that is large and easy to read the temperatures.

It will show the water temperature with a lot of digital accuracies and has a large LCD display screen to read. It is good for both aquariums and terrariums which can be easily readable using the big screen. You can stick the Pet Magasine on the outside of your aquarium glass which will make use of some specific digital reading techniques to measure the water temperature inside.

You can simply attach it by removing the protective cover and stick it. It is also possible to switch easily between Celsius and Fahrenheit by using the single switch. It is not necessary to completely submerge it inside the water but it is made up of a tough outer shell; it is also water resistant. The LR1130 battery is included for better battery power so you may get a long lasting life.

RISEPRO Digital Water Thermometer for Fish Tank

RISEPRO Digital Water Thermometer

It is perfect for taking temperature reading which offers an efficient performance, it is easy to set up the thermometer by just mounting the display kit in the aquarium then put the sensor probe into the water. It is an excellent digital thermometer which comes with an LCD display so it may be easy to read.

This thermometer works efficiently in any tank and also has easy to read the display when to attempt to read the temperature inside the tank. You can get readings either in Celsius or Fahrenheit, and it is highly durable so it will provide long-lasting performance.

This equipment is ultimately designed with high-quality materials which can prevent the water from damaging the entire tank. The RISEPRO Digital Water Thermometer comes with a replaceable battery so the fish in the water will not get shocked if something is plugged into the tank. The maximum range of temperature can be -58 degree F to +158 degree F; it is the best adaptable thermometer which can work better with various kinds of fish tanks and water. If you use this thermometer at the marine water, freshwater or tap water it will give an exact temperature reading.

JW Pet Company Smarttemp Thermometer Aquarium

JW Pet Company Smarttemp Thermometer Aquarium

The JW Pet Thermometer comes with a sleek and compact design and has a green safe area which shows an ideal range of temperature it also has a magnetic substance; this device goes into the fish tank and the magnet moves outward to keep the Smarttemp in a perfect position.

This equipment does not use any suction cups, it has a built-in large LCD display which tells whether it is minimum or maximum temperature with the click of a button you can easily switch between Celsius and Fahrenheit.  The display unit can be mounted to the outside of the tank using the magnet or suction cup.

The Fahrenheit is placed on the white screen background and a green safe zone is placed at the center. This thermometer is ultimately designed with high-quality materials and a unique design combines with a magnet. It is the best high accuracy aquarium thermometer; the Smarttemp also offers a green safe zone which can denote the optimal temperature range.

KollerCraft TOM Temp Alert Digital Thermometer

KollerCraft TOM Temp Alert Digital Thermometer

It is an advanced temperature reading device which can measure the readings very accurately and perfectly; it is constructed with high-quality materials so this device is durable and can last for a long time. It is designed with some special features like an alarm alert it makes a sound when you change water temperature so you can keep your fish fresh and alive.

The LED notifications can give you an alert of the water temperature which is audible also, it is better to use in both freshwater and marine water. It is designed with suction cups so you can easily fix it outside the fish tank; it also represents a low temperature of 75 degrees and a high temperature of 82 degrees. The LCD display shows the temperature and alerts you if it goes beyond the expected range. This thermometer is attached to the 3-foot cord plastic probe, so you can attach the suction cup to the inside wall of your aquarium.

It weighs just 1.6 ounces and can be used for both freshwater and saltwater tanks. This is the best thermometer which gives an exact reading and it offers an excellent performance with a lot of alert features for your fish safety. It is very convenient and easy to use even for beginners. It is also possible to cling the thermometer outwards the tank so you can get special digital reading measurements to gauge the water temperature within.

Wrapping Up!

An Aquarium thermometer is the most useful tool because it tells the temperature of the water. Each and every aquarium owner should use the best thermometer to check whether the temperature in the tank is best! The above-mentioned products can offer accurate temperature readings which are very essential for the fish in your aquarium.


  1. I love to have many fishes in my aquarium. But it never happens, most of the fishes die in my aquarium. When I searched for the reason, I found that these fishes die due to uncomfortness in water. To know the temperature condition in water, I am looking for the best aquarium thermometer. Could you suggest me the right one?