A pool thermometer is an essential item of equipment for measuring the temperature of your pool water.
Knowing the water temperature helps to ensure you are not swimming in water that is too cool resulting in hypothermia, muscle cramps, shivering or sickness.
Soaking in a hot tub that is too hot can cause heat-related medical conditions such as dehydration, dizziness and rapid changes in blood pressure.
Keeping an eye on water temperature also helps to ensure your pool chemicals are working with maximum effectiveness to balance and sanitize the pool water.
We have researched the best pool thermometers available on the market so you can purchase the one that best suits your requirements and budget. Most pool owners simply purchase the cheapest thermometer. However, the lowest priced item may not meet your requirements and may be the least accurate.
Table of Contents
Why Do I Need a Pool Thermometer?
Check the Water Temperature
Obviously, the first reason for using a pool thermometer is to measure the water temperature. Is the water warm enough for swimming or too hot for soaking?
The ideal pool water temperature is above 76F (or 24C).
It’s nice to know before you dive in whether you will be in shock when you hit the water. Even on some bright sunny days pool water can be cool. Sometimes at night the water can be surprisingly warm. Without a pool thermometer you will never know.
When you have small children, you will want to know the pool is warm enough for them to swim. Children can lose body heat quickly in a cool pool resulting in hypothermia, muscle cramps, shivering and sickness.
If the pool water is too cool or spa water is too hot it may aggravate your medical conditions.
Some medical conditions, such as arthritis or muscular pain, may benefit from soaking in warm water.
However, soaking in a hot tub for long periods of time can be detrimental to your health. Medical experts concur that staying in a hot tub for too long has detrimental health risks. Hot water can cause heat-related medical conditions such as dizziness, changes in blood pressure, skin rashes, nausea and dehydration.
Please read our article – How long is it safe to stay in a hot tub?
Pool Chemical Effectiveness
Most pool chemicals work with maximum effectiveness between 60 and 95 Fahrenheit.
In Chemistry, the speed of chemical reactions is directly corelated to the water temperature. That is, the higher the temperature the faster the chemicals react. If you have a cool water pool you may need to add more chemicals to effectively treat the water.
On the other hand, if the water temperature is high chemicals can be evaporated from the pool. This may leave your pool water unbalanced or unsanitary. For example, Chlorine easily evaporates when exposure to hot sun in the middle of the day. This is why you always add pool shock in the evening when the sun is going down. You may need to add more chemicals when your water temperature is high.
Some chemicals, like Bromine, are more effective at higher temperatures. This is why Bromine is used in hot tubs and spas where the temperature is above 75F.
Measure Equipment Effectiveness
When you have a pool heater you will want to check the water temperature to ensure the heater is working correctly. A thermometer is useful for deciding how long to run the water heater.
A thermometer can tell you whether the solar pool cover is making a difference.
How to Select a Pool Thermometer
Types of Thermometer
Analogue Pool Thermometer
These are standard mercury strip thermometers. Rising temperature expands the mercury driving it up the tube to give a temperature readout against a printed scale.
Mercury thermometers are inexpensive, easy to use and tend to last longer than digital thermometers. However, digital thermometers will be more accurate and easier to read.
A floating thermometer will only measure the water at the surface which is usually warmer than at the bottom. A submerged or sinking thermometer on a string can give a more useful measurement of the water temperature.
Digital Pool Thermometer
These products have a sensor probe that is submerged in the water and the temperature is displayed on a digital screen.
Remote pool thermometers have a sensor that is placed in the pool which sends a signal to a receiver or mobile phone.
Digital thermometers require a power source such as batteries, charging or solar cell.
Durability
If you are going to spend your money on a pool thermometer you will want to select one that will last the distance.
Firstly, purchase a proper pool thermometer not just a standard house thermometer. When a thermometer is placed in your pool it is exposed to UV sunlight and pool chemicals. Pool thermometers must be constructed from durable materials to operate in outdoor pool conditions.
Read customer reviews for the recommended thermometers to determine if the product is good quality or not.
Features
There are many products available with many advanced features:
- Digital or analogue readout
- Floating, hanging or handheld
- Storage of temperature data
- Solar powered
- WiFi or Bluetooth remote connection
- Mobile Phone Android or IOS App
Cost of a Pool Thermometer
The cost of a basic analogue (mercury scale) floating pool thermometer will be around $10 to $20.
A floating or sinking mercury pool thermometer is all most pool owners need.
A digital pool thermometer will cost around $20 to $30 and is easier to read.
A wireless pool thermometer with remote readout will cost starting at $40.
An infrared thermometer gun will cost over $30 and has numerous other uses.
A remote monitoring weather station with a wireless pool thermometer will cost upwards of $100. These weather stations have multiple sensors for measuring a range of inputs not just for monitoring your pool.
Inkbird IBS-P01R Wireless Pool Thermometer
This floating pool thermometer is great if you want to monitor your hot tub or pool at any time from inside your house or on your mobile phone anywhere in the world.
It’s perfect during the winter to ensure the pool equipment is working. Simply put it the spa under the cover and check the temperature without going outside in the snow.
Use it in your aquarium or pond to keep your fish safe from temperature fluctuations.
Many mothers use it in the baby bath to ensure the water is warm enough.
Power Supply: 2 * AAA batteries
Transmission distance: up to 300 ft.
Temperature & Humidity measurement.
Samples the temperature every 10 seconds for a real time display.
eLander Floating Pool Thermometer
Here is a quick and dependable solution to checking and maintaining the right pool temperature.
Its main features are it’s easy to use, has a large display, comes with a long string and displays both Celsius and Fahrenheit readings.
It does not require batteries and is easy to remove and store when not in use.
The price is very low for a good product.
Read the customer reviews on Amazon which prove everyone likes this pool thermometer.
Weather Station with Floating Pool Thermometer
This great product monitors local and remote sensor temperature and humidity. The product can support up to seven external sensors and connect to the internet.
The 7-channel floating pool and spa thermometer is perfect for home owners that want to monitor and send alert notifications when the pool or spa is too hot or cold.
The console includes a temperature and humidity sensor. Two additional wireless sensors are included and you can purchase up to five more additional sensors. The sensors connect to the console via Radio Frequency (915 MHz). The console connects to your WiFi router (2.4 GHz).
The product is easy to setup with a web page that explains everything to get your station operational.
Digital Solar Floating Pool Thermometer
This solar pool thermometer is constructed of high-quality plastic materials. It has a simple design and classic appearance. The digital scale is clean and bright and easy to check. It is highly accurate with small error measurement.
It’s supplied with a floating rope to secure the thermometer to the side of the pool.
The temperature probe senses the water temperature deeper in the water, so that the temperature measurement is more accurate. You don’t just want to know the surface temperature! Pool water is always cooler below the surface.
This product is definitely a great choice for your pool.
Etekcity Infrared Thermometer Gun
This product is a #1 best seller on Amazon.
The product will not only measure the temperature of your swimming pool but can be used on countless other applications around the home. Use it for cooking, ovens, BBQs, air conditioning, refrigerators, car engine, heaters, etc.
Infrared technology makes it simple to measure the surface temperature of any object especially temperatures below the freezing point and above the boiling point.
Warning: NOT FOR HUMANS: The thermometer can’t measure the internal temperature of a person, Temperature readings from this devices are for inanimate objects only.