Although chlorine tablets and granular chlorine contain some Cyanuric Acid as an ingredient, the amount contained is merely a trace. Therefore, chlorine users will have to add Cyanuric Acid periodically. Cyanuric Acid is typically packaged and sold as either "Conditioner" or "Stabilizer," depending on the manufacturer.

Cyanuric Acid ("Conditioner" or "Stabilizer") will definitely need to be added after a pool is drained, cleaned and refilled, as the tap water that is used to refill your pool contains almost no Cyanuric Acid. If there are just trace amounts of Cyanuric Acid in the pool water, then it does not matter how much chlorine (or shock) is added. The majority of it will be destroyed by the sun.

The recommended ideal range for Cyanuric Acid is between 30-80 ppm. Poolmanual.com recommends a reading closer to 40 ppm as ideal. 40 ppm is high enough to prevent the sun from destroying chlorine's effectiveness. Since chlorine tablets and granular chlorine are CYANURATES, a trace amount of Cyanuric Acid is added to the water as chlorine is continually added to the pool. Eventually then, the Cyanuric Acid reading will eclipse 100 ppm (maximum that is accepted), which will cause your pool to hold too strong of a continual chlorine reading. There is no chemical to reduce Cyanuric Acid. It can only be reduced by either partially or completely draining the pool. It will take many years of adding chlorine tablets or granular chlorine to eclipse that 100-ppm reading.

TESTING FOR CYANURIC ACID: There are test strips that include Cyanuric Acid-these are expensive. There are also test kits that include Cyanuric Acid-these are typically not too expensive. There are also specialized and isolated Cyanuric Acid test kits. But, since Cyanuric Acid only has to be tested approximately once per month, or as-needed-when you are having a hard time registering any chlorine reading at all or when you have a constant high chlorine reading-you are well advised to bypass purchasing any type of Cyanuric Acid tester. Rather, go visit your local pool professionals and have them test your Cyanuric Acid, as well as the rest of your chemicals, on the computer.

WHEN TO ADD CYANURIC ACID: Basically, Cyanuric Acid needs to be added when your pool professionals advise you to add it. Again, since Cyanuric Acid only has to be tested approximately once per month, or as-needed-when you are having a hard time registering any chlorine reading at all or when you have a constant high chlorine reading-you are well advised to bypass purchasing any type of Cyanuric Acid tester. Rather, go visit your local pool professionals and have them test your Cyanuric Acid, as well as the rest of your chemicals, on the computer.

The recommended range for Cyanuric Acid is 30-80 ppm. If your Cyanuric Acid reading is lower, add Cyanuric Acid. Even if your Cyanuric Acid level is between 30-40 ppm, if you are having problems registering any chlorine reading, add Cyanuric Acid. But again, before you add Cyanuric Acid, go visit your local pool professionals, have them test your chemicals on the computer, and then listen to their advice.

NOTE: When you drain your pool for any reason and start over with fresh tap water, you will need to add Cyanuric Acid. Tap Water contains only a trace of Cyanuric Acid. It is very common to refill your pool, have a Cyanuric Acid test taken on the computer of your local pool professionals, and register a reading of only 5-10 ppm. Again, the ideal range is 30-80 ppm. It is best to initially maintain close to a 30-40 ppm reading; do not attempt to reach that 70-80 ppm reading at the start. The reason is that as you add chlorine tablets or granular chlorine, you will be adding trace amounts of Cyanuric Acid (chlorine tablets and granular chlorine are stabilized, which means they contain trace amounts of Cyanuric Acid as an ingredient). Once Cyanuric Acid reaches 100 ppm, your chlorine reading will constantly be too strong. There is no chemical to lower Cyanuric Acid. Rather, you would need to drain the pool and start over with fresh water. And remember, when you have to start over with tap water, you will have to again add Cyanuric Acid. Therefore, register an initial Cyanuric Acid close to 30-40 ppm. It will take years to reach or eclipse that 100 ppm maximum parameter.

HOW TO ADD CYANURIC ACID: Read the instructions on the label. Some manufacturers require the Cyanuric Acid to be diluted in a bucket of water and then poured into the pool while other manufacturers require the Cyanuric Acid to be broadcast directly from the container into the pool. Be Aware: some manufacturers offer an alternative option on how to add the Cyanuric Acid-they recommend pouring the Cyanuric Acid directly into the skimmer. Again, poolmanual.com does NOT recommend pouring ANY chemical into a skimmer.

NOTE: Cyanuric Acid is typically packaged and sold as "Conditioner" or "Stabilizer."

HOW TO LOWER CYANURIC ACID: There is no chemical to lower Cyanuric Acid. Once your Cyanuric Acid reading reaches or eclipses the 100 ppm maximum parameter, you will need to drain your pool, either partially or completely. It is best to drain the water completely. It will take years to reach the 100 ppm maximum reading for Cyanuric Acid. During years of adding various chemicals, you will build up a high reading of TOTAL DISSOLVED SOLIDS. Therefore, if you initially started with a Cyanuric Acid reading between 30-40 ppm, by the time Cyanuric Acid reaches its maximum parameters, if it has been some time since the pool was drained, then drain it completely and start over. If you decide to drain the pool all the way, it is best to contract your local pool professionals and pay them to perform a DRAIN AND ADD-it really is an investment versus a service call. Remember, if you do drain the pool all the way and start over with fresh tap water, you will need to add some Cyanuric Acid ("Conditioner" or "Stabilizer") once the pool is refilled; tap water contains almost no Cyanuric Acid. But again, only attempt to reach a 30-40 ppm reading at the outset.

If you live in a region that winterizes and it is near the end of the season, or if you need to use the pool for a special event soon, then just drain the pool partially to eliminate some of the Cyanuric Acid level and refill the pool with tap water. This should keep you within the ideal range. Example:

Your Cyanuric Acid reading is 120 ppm and this is causing you to constantly hold too high of a chlorine reading (a consistent 5.5 ppm or higher Free Chlorine reading). This high chlorine reading is probably burning your eyes and skin, and it may soon begin to assist in damaging some of your pool equipment. You are having an "end-of-the-summer" party for all your friends and family members. You will probably winterize your pool within 1 month of this party. You do not want to start over for less than 1 month of swimming. Rather, drain the pool approximately ¼ down, and then refill it. This may drop your Cyanuric Acid reading close to 75 ppm. As you refill the pool, since tap water contains almost no Cyanuric Acid, your reading will still only be close to 75-80 ppm.

BACKWASHING AND CYANURIC ACID: Read the instructions on the label. Most manufacturers of Cyanuric Acid are very explicit in requiring that you do NOT backwash for 48-72 hours after adding Cyanuric Acid. If you backwash, you will lose your Cyanuric Acid residual. If your (sand or DE) filter is dirty and your Cyanuric Acid is low, backwash first, and then add the Cyanuric Acid. Once added, do NOT backwash for the required 48-72 hours.

NOTE: Backwashing is the process to clean a sand filter or a DE filter.
 

 
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