When you decide to keep pet fish, there’s a lot of things to remember. You’ll need to make sure they have the right tank and the right substrate (be it aquarium sand or fish tank gravel), that the water is filtered and clean and maybe even include some rocks, plants and other decorations in the aquarium to keep your fish happy. But what about the temperature of the water?
Ensuring that the water temperature is correct for your fish is very important to their well-being. Of course, the easiest way to measure temperature is to use a thermometer, but with so many different types of fish tank thermometers out there, how do you know which one is going to be right for you?
Fortunately, we have complied a buying guide below giving you all the information you need on choosing the best aquarium thermometer. We’ve even included some of our top picks out there on the market today. So, if you’re ready to get your fish tank set up, keep reading on.
Do I Need An Aquarium Thermometer?
Fish must be kept at a certain temperature to stay healthy and happy. Most owners will use a heater to keep their tank at the right temperature for their fish, and the best aquarium thermometer can help you to monitor this temperature and keep the water just right. While some heaters come with a thermometer built in, it’s never a bad idea to be able to confirm the temperature with a more accurate thermometer.
One of the best things about the best aquarium thermometers is their accuracy. Some of these thermometers can tell you whether the water is even 0.1 degree out, so you can make adjustments and ensure your fish are comfortable. This also helps you to see if there are any issues with your tank or heater and deal with it accordingly.
Types Of Aquarium Thermometers
There are a few different types of aquarium thermometers for you to choose from. All are suitable and it will be up to you to decide which one is going to work in your tank.
A digital thermometer is usually a probe paired with a digital display. They normally read the temperature in both °C and °F and can give an accurate reading. Some can be left in the tank constantly to monitor the temperature and they might even come with an alarm that lets you know when the temperature has changed.
While digital thermometers can be the most expensive, they are very durable. They can also be less hassle because some of them are wireless, making them easy to use.
Standing or Floating
A floating or standing thermometer is a thermometer that is fully submerged in the water. This can sometimes make them difficult to read, but some use different colors to indicate whether the temperature is correct or not.
These thermometers are often made of glass which can make them easily breakable. Some use suction cups to stay in place, while others use magnets. Some even have weights at the bottom and are free-standing. While these thermometers are cheaper, you may need to use more of them to get an accurate reading, especially if you have a large tank.
Stick-on thermometers are stuck on the outside of the tank, which can make their accuracy less reliable. They are also often called LCD thermometers because they have some sort of LCD display. Unfortunately, their readings can be impacted by the temperature of the room the aquarium is in, the sun and fans or heaters in the room. Therefore, these thermometers are not always advised, unless you ensure the room stays at the correct temperature too.
Things To Consider In The Best Aquarium Thermometer
There are a few things to consider when buying the best aquarium thermometer to ensure you get the right one for your tank.
As we have mentioned above, there are different types of aquarium thermometers. A digital thermometer can be easier to read, but is more expensive than a standing or floating thermometer. There are also stick-on thermometers that stick to the outside of the tank. Each of the types have their own advantages and disadvantages.
The best aquarium thermometer needs to be accurate. Otherwise it can’t be considered ‘the best’ and there is not much point in having one! Sometimes, even if the water temperature is only a few degrees out, it can really affect your fish. Therefore, ensuring the water is accurate and kept at the right temperature is very important. The best aquarium thermometer should be accurate to within +/-2°F
You will want your thermometer to be durable, otherwise you’ll constantly be buying a new one. These devices need to be able to survive in water and also be fairly unbreakable. If a glass thermometer breaks in the water, the broken shards could harm your fish. A durable thermometer can be more expensive, but it is worth it.
Ease Of Reading
Just like a thermometer needs to be accurate, you also need to be able to read it! If you have poor eyesight, we recommend a digital thermometer. These can be easier to read than liquid-filled models and, while they are more expensive, they can be better in the long run.
Digital thermometers are powered by batteries or by the mains. This is very useful, until you get caught out with a dead battery or you have a power outage! Stick-on or standing and floating thermometers don’t require batteries and so are a good option to have as a backup alongside a digital thermometer.
If you’re ready to find the right thermometer for your aquarium, take a look at the best aquarium thermometer products we recommend below. All of these are available to you on Amazon.
The Best Aquarium Thermometer Reviews
These digital thermometers from Zacro give accurate temperature readings to within 1 degree. Easy to use, you submerge the probe into the water and can suction cup the wire to the side of the tank, so you get a constant reading. The large LCD display on this digital thermometer is easy to read, perfect if your eyesight isn’t too good! The temperature range on these thermometers is -50 degree Celsius to +70 degree Celsius, perfect for a large range of tanks and fish species. They are battery powered and therefore wireless, too. Even better, with this two pack, you can use both these thermometers on a larger tank and still get an accurate reading.
This digital thermometer is completely wireless and actually sticks to the side of your fish tank. The backside has a temperature sensor stick that is placed on the outside of your tank and it is accurate to 0.1°. This thermometer reads from 0°C to 70°C / 32°F – 158°F and is very easy to use with the large touch screen display. Great for reading from far away (or if your eyesight isn’t so good!), the compact design doesn’t stand out too much but still gives easy-reading. This best aquarium thermometer is great for any type of tank and is very durable.
This floating thermometer from Marina comes with a suction cup to keep it in place. Easy to read, there is a safety zone indicator so you can be sure the temperature of your tank is in the right range. Standing 4.24 inches tall, this thermometer is perfect for tanks of many different sizes and still offers a display that is easy to read. It does not require any batteries or mains power and can be left in the tank indefinitely, making it easy to use. It provides temperature readings in Centigrade and Fahrenheit and is usable in both freshwater and saltwater tanks.
This digital thermometer from RISERPO is easy to use and can be set up in minutes. Battery powered, you can suction cup the display to the side of the tank and leave the probe in the water, giving you a continuously accurate temperature reading without the need for lots of wires or a complicated system. The LCD display is large and easy to read and gives an accuracy of +/- 1 degree Celsius. It measures in both Celsius and Fahrenheit (-58°F – 158°F / -50°C – 70°C) and is perfect for many different water types.
This is a stick-on thermometer from LCR Hallcrest that is accurate and easy to read. You can mount this thermometer to the outside of your tank and there are colors to indicate where the temperature lies and whether the water is in the correct temperature zone. Alongside the color, the numbers read large on the thermometer so you can be sure to know what the temperature is. With no batteries or wires needed for this thermometer to work, it is very easy to read and use and has good durability. You can also easily move it when needed, which is an added bonus.
Another stick-on thermometer, this thermometer from Fluval is compact and perfect to use as a back up to a digital thermometer. Reading both in Celsius and Fahrenheit, this thermometer ranges 64 to 86 degrees Fahrenheit and comes with an adhesive backing which makes it easy to mount to the outside glass. While some users have reported it can be a little difficult to read, it does have colors to indicate whether the temperature of your water is in the correct zone or not. The small design makes it great for even the tiniest aquariums and doesn’t stand out too much, either.
Another floating thermometer from Marina, this thermometer measures in both Celsius and Fahrenheit and ranges from 30 to 120 degrees Fahrenheit. Easy to use, you can suction cup this submersible thermometer to the side of your tank for a constant temperature reading. The colors on the thermometer help to indicate whether the temperature is in the correct zone or not, making it very easy to read. With no batteries or wires required, this liquid thermometer can be used straight away and is always reliable. It is also suitable for both fresh and saltwater aquariums.
This thermometer from Cooper Atkins isn’t specifically designed to be an aquarium thermometer, but as a waterproof thermometer it can be used as one! Small and compact, this thermometer is particularly useful if you want to double check the accuracy of other thermometers you may be using from time to time. You can easily stick the probe into the water and receive an accurate reading, ranging from -40 to 450°F. You can also switch between Celsius and Fahrenheit easily. Battery powered, you don’t need to worry about wires or mains electricity and it is aways easy to use.
This thermometer from JW Pet is placed inside the tank and secured by a magnet on the outside. Battery free and wireless, this thermometer is easy to use and has large numbers for you to read from. A colored section on the thermometer indicates a safe zone for your water temperature and, reading in both Celsius and Fahrenheit, it is very simple. The fact the thermometer stays in the water gives a more accurate reading and the magnet allows you to easily move the thermometer around the tank when it comes to cleaning.
This unique thermometer from Inkbird is designed to be paired with your water heater and allows you to adjust the temperature as and when is needed. All you need to do is place the two probes into the water and pair the thermometer with your phone. If the water changes temperature, an alert will be sent to your phone and you can adjust the temperature accordingly. This thermometer measures temperature between -40℃ – 100℃/-40℉ – 212℉, giving a great range. It does require electricity to work but can be left plugged in safely without the worry of batteries running out.
Best Aquarium Thermometer FAQ’s
Are digital thermometers more accurate?
Digital thermometers are generally the most accurate thermometers because they have been calibrated properly. However, there are some digital thermometers out there that aren’t accurate, so it can vary completely! It all depends on how long they ‘hold’ their calibrated accuracy.
What temperature should my fish tank be?
The correct temperature of your tank water depends on what type of fish you are keeping. Most tropical fish need to be kept in water with a temperature between 76 and 80°F, while other fish prefer temperatures that are lower.
Ensuring you keep the temperature of your aquarium correct is vital to your fish enjoying a long and happy life. The best aquarium thermometer can help you to ensure the temperature is right and, with so many accurate models out there today, you will be able to find one that can tell you if you are even 0.1 degree out. Whether you want a digital thermometer or prefer a more classic liquid-filled thermometer, there is one that will meet all your needs and help to ensure your fish are comfortable. Which one are you going to pick?
Check out our other Fish Tank, Food & Accessories posts here:
- Best 20 Gallon Fish Tank Guide
- Best 5 Gallon Fish Tanks Guide
- Best Aquarium Vacuums Guide
- Best Aquarium Gravel Cleaners Guide
- Best Water Conditioner For Fish Tank Guide
- Best Aquarium Rock Guide
- Best Aquarium Plants Guide
- Best Fish Tank Decorations Guide
- Best Fish Tank Gravel Guide
- Best Aquarium Sand Guide
- Best Goldfish Food Guide