Best Aquarium Thermometers for Sale

Types of aquarium thermometers

Before choosing any thermometer, it is necessary to know the types, as this way you will know which one is the best for the aquarium, tank or fish tank.

Floating thermometer (tinted alcohol)

This type of thermometer is only used in limited cases because it has mercury, which is a toxic compound. In addition, glass is used in its manufacture to encapsulate the contents of the device. The particularity of this thermometer is that when it is thrown into the water it floats, since it is balanced with lead or steel weights, so that it can be kept vertically in the aquarium.

Another peculiarity of this fish tank thermometer is that it uses scales of degrees Celsius or degrees Fahrenheit, in addition, it can be useful for aquarium practices, but it is not very accurate for studies. If you choose this thermometer, you must take into account that it must always be immersed in water in order to take the correct temperature reading. Also, it is important that it is not exposed to the sun directly, since it can cause the temperature to rise to such an extent that it can cause bubbles that cannot be eliminated.

Adhesive thermometer

The adhesive thermometer is a sticker that sticks to the outside of the glass of the aquarium, fishbowl or tank, but how does it work? Well, this thermometer works by means of a numbered grid that changes color with temperature.
The use of this aquarium thermometer is not highly recommended, although it can be very practical, since it is not very accurate and is difficult to read. The low accuracy of this model is due to the fact that an aquarium only consists of a wall of 4 or 5 mm thick, so the slightest airflow may cause the reading to change.
If you want your fish to be in good health, do not acquire such an unreliable instrument as this one.

Digital aquarium thermometer

If you are interested in an accurate instrument for your freshwater aquarium, it is best to purchase a digital aquarium thermometer, as it is quite accurate in reading the temperature. Its ease of operation is due to the fact that it uses batteries or is connected to a network, but this will depend, first of all, on the model you choose.
One of the peculiarities of this thermometer is its robustness and rigidity, has the ability to store data, so you can record the highest and lowest temperature when you are not near the aquarium. It also measures both the temperature inside and outside the aquarium, so you can be confident of its accuracy.
Another peculiarity of this thermometer is that it can come with an alarm function that will warn you when the temperature goes out of the chosen range.
In the market there is a great variety of these that are very precise and at a good price, but if you look for more functions and pretensions, their price will rise, because they have more innovative designs and their materials are more expensive.
If you choose this kind of aquarium thermometer, keep in mind that its probe is submersible so that its reading can be accurate, and never choose a thermometer that has the probe outwards, as it could give you incorrect data in the measurement.

Which aquarium thermometer to buy?

Now that you know what types of aquarium thermometers are available, you have to consider what factors are most relevant, to make the final decision.
Remember that the health of your fish will depend largely on the choice of a quality thermometer.

Reliability (accuracy of measurements)

This is an important factor, but before you do this, first set the size of the tank before deciding which aquarium thermometer to buy, as this will indicate the most reliable model.
Keep in mind that the thermometer must be totally reliable for your fish to be in good health. Speaking of reliability, among the types mentioned above, digital and mercury thermometers are quite accurate, since they are not influenced by the room temperature.


Another factor to consider is the durability of the fish tank thermometer. In this regard, it is better to purchase a fully submersible one rather than a partially submersible one, since submersible thermometers are more durable and less likely to cause temperature-related failures.
Keep in mind that no matter how they are installed or what type they are, it is best to replace most of them once a year…except for the electronics, which obviously have a much longer life.

Price of thermometers

Another thing you should consider is the amount of money you will spend for the thermometer, as your budget determines which one to choose, but in general, they are not that expensive and all fit your budget.
It is better to research among the types the aquarium thermometer that best suits your needs, and never skimp on the price, since the most expensive thermometers have unique features that can certainly go a long way in the accuracy of the result, such as digital thermometers that are certainly the best value for money.