pool water testing

A Guide to Pool Water Testing

The process of maintaining a clean swimming pool requires pool owners to regularly test their water quality to ensure everything is functioning as it should. Routine testing guarantees that the water remains free of contaminants, and retains its crystal clear clarity. 

In today’s guide, we will walk you through the importance of testing pool water, the frequency in which you should test, reliable testing methods, as well as when you may need to call in the professionals.

Why you should test your pool water

Testing your pool water is an important part of pool maintenance for a few different reasons. Testing on a regular basis ensures the health and wellbeing of those choosing to swim by maintaining balanced chemical levels, which can prevent irritation in both the skin and eyes.

Additionally, testing the water’s chemistry helps prolong the life of your pool equipment by preventing scale build-up and corrosion. Imbalanced water can cause a buildup of algae and bacteria, making the swimming pool unsightly and uninviting.

How often should you test pool water

The frequency in which your pool water needs to be tested relies primarily on how frequently the pool is being used. During the busy swimming seasons, it is best to water test around one to two times a week. Additionally, if there is any type of extreme weather, it may be beneficial to check the chlorine and pH levels once it’s passed.

Here are some guidelines on how often you should check your pool’s levels:

  • Chlorine and pH – 2 to 3 times a week
  • Total alkalinity – Once a week
  • Calcium hardness – Once a month
  • Total dissolved solids – Once a month
  • Metals – Every 3 to 4 months

When does a professional need to be involved?

Notice frequent issues with water clarity? Are the pool water samples coming back consistently imbalanced? If there’s recurring issues, it may be time to call in a professional to resolve the problem. Bringing in your water for an in-store test may be a good place to start.

What are the best ways to test pool water?

For pool owners, there is always more than one way to test your water quality. Below are four ways homeowners can monitor the quality of their pool’s water.

Pool testing kits

Test kits are available that use color charts and reagents to determine your pool’s water quality. These tests are often very accurate and provide detailed results across multiple tests.

Testing strips

Need a quick and accurate test? Test strips simply come in contact with pool water and produce a chemical reaction that delivers a certain color. Using a chart, pool owners can determine if the pool has any potential imbalances. The simplicity of this method makes it a staple tool in pool care basics.

Digital test kits

Digital apparatuses are available for pool testing as well. These devices are great pool monitoring systems that assess the top of the water – no deeper than elbow deep – to determine what the chemical balance of your pool is. 

In-store testing

Lastly, home owners have the option to opt for in-store testing. While not as common, this method of testing can provide a detailed analysis of your pool’s water, guaranteeing an accurate reading. 

What should you be measuring? 

While you may know to observe chlorine levels and low pH levels, there are a few other factors to observe when testing water. 

Ideal measurements are as follows:

  • pH: 7.4–7.6
  • Free Available Chlorine: 2.0–4.0 ppm
  • Total Alkalinity: 80–120 ppm
  • Calcium Hardness: 200–400 ppm
  • Cyanuric Acid: 40-100 ppm ppm
  • Metals: 0 ppm
  • Phosphates: 0 ppb
  • Total Dissolved Solids: 0-2,500 ppm
  • Salt: Based on the salt system salinity requirements  (follow this guide!)


Monitoring your water’s pH levels ensures that the water is not too basic or too acidic when it’s time to swim. An improper balance could lead to skin irritation and scaling.

Calcium hardness

In order to prevent scaling and buildup on your pool equipment, it is important to monitor the Calcium levels in your water. To prevent corrosion, try to maintain a level of around 200 to 400 ppm. 


Total alkalinity helps stabilize your pool’s pH levels, ensuring there’s no rapid spikes in the pool’s chemical makeup. Alkalinity coming in a bit too hot? Check out our guide on lowering your pool’s alkalinity. 


While chlorine is an essential part of maintaining your pool, it is important to make sure chlorine levels are balanced in order to protect those swimming, as well as the equipment servicing your swimming pool. Appropriate levels help disinfect the water and prevent the development of algae and bacteria growth. 

It’s also important to note that when testing multiple things at once, an improper chlorine balance can affect pH and alkalinity.

Cyanuric acid 

Cyanuric acid, also known as stabilizer, protects chlorine from being broken down by sunlight. Maintaining levels between 40 and 100 ppm helps ensure your chlorine remains effective.

Foreign chemicals 

Every once in a while, it’s good to test for copper and iron levels. These unexpected chemicals can find their way into your pool through a number of different avenues. To protect your pool equipment, the pool surface, as well as those hoping to swim, be sure that foreign chemical levels are low or non-existent.

Pool maintenance is a breeze with GPS Pools

At GPS Pools, we’re proud to provide you with the best pool chemicals, pool equipment, treatment plans, and pool technicians to help you keep your at-home oasis in pristine condition. We aim to be your one-stop-shop pool store in the greater Tampa area! Come see us today!