How to test pool water

How to test pool water

If you own a swimming pool, it becomes a responsibility (and necessity) to maintain the pool water. 

A dirty pool with imbalanced water can lead to serious health hazards and malfunctioning pool equipment. 

Regular pool water testing will inform you about your pool’s health and give you the foresight to detect any upcoming problems. 

Follow this step-by-step guide on how to test pool water. 


Why is it essential to test the pool water 

A clean-looking pool and crystal-clear water are not absolute indicators of your pool’s condition. 

Visible signals like cloudy pool water, debris, scaling, or mold clearly show a problem with your water chemistry. 

However, things like pH, alkalinity, total hardness, sanitizer (chlorine/bromine), etc., are crucial parameters that can be measured only by testing. 

Below are four reasons to test your pool water:

  • Make informed decisions: Some pool owners habitually add pool shock or sanitizer to the water without prior testing. Actions like these can result in severely imbalanced water leading to other problems. 
  • Eliminate health hazards: If the pH of your pool water falls too low (becomes acidic), it can cause rashes on your skin. If the pH goes too high, it can cause eye irritations and other skin problems. 
  • Save on chemicals and effort: Regular pool water testing helps you stay one step ahead of any upcoming problems like the onset of algae or white water mold and low sanitizer levels. It saves you from hectic cleaning and chemical treatments that follow these problems. Remember that prevention is always better than cure.

  • Protect your equipment: Unchecked factors like pH and hardness can severely damage your pool equipment in the long run. 

A picture of a liquid pool tester

What ways are there to test the pool water? 

There are four ways to test the pool water. Each of them differs in accuracy, effort, and time involved. The method you choose will eventually depend upon your convenience and requirements.

Pool Test Strips

It is by far the simplest and quickest method of testing pool water. However, it is also not the most accurate or elaborate. A pool test strip can measure among two to seven parameters depending upon its design. 

All you have to do is to dip the strip in pool water and wait for about 15 seconds to get the readings. 

Check out our guide on how to use pool test strips to know more. 

Pool Test Kits

These kits include a couple of vials, several reagents, and a user manual. Pool test kits are very accurate; it takes about two to ten minutes to test the pool water. 

Using them involves filling the vials with pool water and mixing them with appropriate reagents. The resulting colored solution has to be matched with the user manual to evaluate the results. 

Follow this guide on how to use pool test kits for detailed info.  

Pool Water Monitor

Using a digital pool monitor is the easiest and most accurate method of testing pool water at home. It automates the testing task, and many monitors allow you to control them remotely. 

For example, our Sutro Pool Water Monitor System tests the pH, alkalinity, sanitizer (chlorine/bromine), and temperature levels of the pool water and sends them over to the mobile app. It even tells you how to rebalance the water to make your life easier. 

Local pool store 

If you need help with testing the pool water or help to figure out the problem with water chemistry, get it tested at a local pool store. Sometimes uncommon factors like metals (iron, copper, etc.), TDS, phosphates, or salt can cause the water balance to fluctuate. 

How often should I test the pool water? 

Ideally, you should test your pool water every couple of days, mainly if your pool is used often. If you are a bit of a procrastinator or have a busy schedule, you can test twice every week. Also, keep these considerations in mind as well:

  • Always test the water before entering the pool, especially if you added pool chemicals recently.

  • Test the water after rain or a storm.

What are the normal pool chemical levels? 

These are the normal levels of the most basic water chemistry parameters in a pool:

  • pH: Between 7.2 and 7.8.

  • Total Alkalinity (TA): 80 - 120 ppm (parts per million)

  • Free Chlorine: 2 - 4 ppm

  • Cyanuric Acid (Stabilizer): 20 to 50 ppm

  • Total Hardness: 200 - 400 ppm

  • Total Chlorine: 1 - 3 ppm

  • Total Bromine: 3 - 5 ppm


Regularly testing your pool’s water keeps you informed about the water chemistry and upcoming problems. You can use test strips, liquid test kits, or a digital pool water monitor for testing. You can also take a sample of your pool water to a local pool store if you are unsure about the issue. 

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