Cyanuric acid is a chlorine stabilizer commonly used in outdoor swimming pools. The presence of this substance is fine as long as it is in the range of 30 to 50 ppm (parts per million). You should periodically check the concentration of cyanuric acid in the pool water to make sure it is within these values.
Steps
Method 1 of 2: Turbidity Test
Step 1. Get a test kit
The turbidity test kit should contain a special glass tube, a plastic container, and chemical reagent packs. Each kit can vary by manufacturer, but many also contain a plastic pipette and spoon or stirring rod.
- The glass tube should have a black dot or line on the bottom. This sign is critical to a successful test, so make sure it's there.
- Sometimes the test tube and the plastic vessel are connected, but there should still be at least two separate compartments.
Step 2. Fill the container with the water to be tested
Collect 25 ml of sample. You can do this by immersing the plastic container directly in water.
- Follow the instructions you found inside the kit. Some will ask you to collect more or less water.
- Some kits will provide you with a plastic container with a lid. If this is your case, you can mix the reagent with the water to be tested by capping the container and shaking it for about 30 seconds.
- If you need a spoon or stirring rod and need to use your own, choose plastic or glass.
Step 3. Add the turbidity analysis solution
Pour a package of chemical reagent into the water sample. Use a spoon or wand to stir gently until the powder has dissolved.
- Wait a minute before proceeding. This will allow the chemical reaction to complete itself.
- The reagent reacts with cyanuric acid in the water to create turbidity. The more cloudy the water, the higher the concentration of cyanuric acid.
Step 4. Pour the resulting solution into the glass cylinder
Use the pipette to transfer the liquid into the marked tube, one drop at a time.
- You should hold the tube over a white or light surface so that the black mark can be clearly seen.
- Look into the glass cylinder from above as you transfer the drops of solution.
Step 5. Stop when the black mark disappears
As soon as you can no longer see the bottom mark, stop adding liquid.
- The black mark must disappear completely. Don't stop if it's still partially visible.
- Make sure you are looking at the tube from above and not from the side.
Step 6. Check the fluid level
This line will tell you the concentration of cyanuric acid in your sample.
- If the mark disappears when the liquid is below the 100 ppm line, the cyanuric acid concentration is greater than 100 ppm. If it disappears above the 10ppm line, then it's less than 10ppm.
- The ideal range for pool water is between 30 and 50 ppm.
Step 7. Retest if necessary
If the cyanuric acid level is above 100 ppm, it will be necessary to dilute another water sample and retry the test to determine the exact value.
- Take another sample of about 20ml of water. Add 20ml of distilled water and mix.
- Run the test again in the same way, but this time use the new diluted sample.
Step 8. Adjust the water according to the results and do the test again
Add more cyanuric acid or fresh water to the pool and check the levels again after the acid has been able to distribute itself evenly.
- Usually, it will take about four hours for the water to be ready to be retested.
- Check again using the same steps you did for the first test.
Method 2 of 2: Using the Test Strips
Step 1. Purchase test strips
Those to detect cyanuric acid have a specific chemical composition to detect this acid.
- You only need one strip to perform the test, but it is better to buy a pack as you will need to take the test at least once a month.
- Often the strips for testing cyanuric acid are sold separately and not in a kit, since you can immerse the strip directly in the pool water without having to collect a sample. Make sure the package you buy also contains a scale to identify the color of the strip.
- These are general guidelines only, so you will need to read the instructions in the package before using the strips. If something different is written, follow the ones inside the package anyway because they may be specific to that product.
Step 2. Immerse the strip in the pool water
When you are ready to take the test, take a strip and immerse the part with the detector in the water for 30 seconds.
- The chemicals present will react with the cyanuric acid contained in the water, producing a color on the strip.
- Remember that the specific immersion time of the strip in water varies depending on the manufacturer. Thirty seconds is a conventional time, but it could be more or less.
Step 3. Compare the color on the strip to the scale on the package
Remove the strip from the water and compare its color with that of the identification scale shown on the packaging of the strips.
- The color or shade on the strip will match one of those on the scale. Each color indicates a certain level of cyanuric acid, and these values should be indicated on the scale.
- Many strips measure up to 300 ppm.
- Remember that the ideal concentration of cyanuric acid is between 30 and 50 ppm.
Step 4. Adjust the water according to the results and repeat the test
If you need to add cyanuric acid or dilute the water, do it now, then run the test again.
You must give the acid time to distribute itself evenly in the water before repeating the test. The instructions for the strips usually state how long you will need to wait, but typically this is at least four hours
Advice
Learn the benefits of cyanuric acid. In the right amount, it protects chlorine from ultraviolet rays, thus reducing the loss of chlorine over time. In this way, the pool will be disinfected longer and more effectively
Warnings
- Check your cyanuric acid level often. You should do this at least once a month, but some experts recommend doing it once a week as well. You should test the concentration every time you add new water to the pool.
- Learn the disadvantages of cyanuric acid. In large quantities it can reduce the disinfectant capacity of chlorine: bacteria can increase in the water and endanger health.
