Product Dose

When used, the ideal range for cyanuric acid is 30 – 50 ppm. The concentration should not exceed 100 ppm. Cyanuric acid is not recommended for indoor pools or spas where protection from sunlight is not necessary.The 100 ppm limit is a common consensus among health authorities, for example:

There is a degree of uncertainty in setting this value, but the consensus decision is not entirely arbitrary. The following factors were considered when setting the limit for cyanuric acid:

• Effective use levels of cyanuric acid;
• Cyanuric acid/chlorine equilibria;
• Effect of cyanuric acid on Oxidation Reduction Potential (ORP); and
• Effect of cyanuric acid on chlorine kill rates.

Test kits and strips are available for testing the cyanuric acid concentration to ensure that it is within the proper range. If the cyanuric acid concentration needs to be reduced the following approaches may be used:
 

• Partially drain and refill the pool
• Increase backwash times or frequency
• Follow appropriate water replacement intervals

At above 50 ppm of cyanuric acid, the time it takes to kill bacteria in the water is longer compared to swimming pool water without cyanuric acid. Also, as the level of cyanuric acid builds up, the chlorine will become increasingly less effective in keeping the water clean and problems such as increased cloudiness and exceeding combined chlorine limits can occur.

Note :

• Cyanuric acid and stabilized chlorine (dichlor or trichlor) should only be used in outdoor swimming pools. It should never be used in indoor swimming pools, spas or hot tubs.
• Both dichlor and trichlor release cyanuric acid to the pool water. It is not necessary to put additional cyanuric acid into a pool that uses dichlor or trichlor.
• Pools that use cyanuric acid are required to maintain a free chlorine residual of 2.0 ppm.
• Cyanuric acid should be tested at least once a month.
• Cyanuric acid levels must be maintained below 100 ppm.
• Partially drain pool and add water to reduce cyanuric acid concentration.