[pcm81]

Cyanuric acid is used in pools as chlorine stabilizer. The problem with CYA is that when concentration gets too high it reduces efficiency of chlorine. The target range is 30ppm-50ppm. There does not seem to be any commercially available additives to reduce concentration of CYA.The most commonly suggested method is dilution, which requires large amount of water for a decent size pool. My question is: are there chemicals, that would be safe to add to the pool to reduce CYA concentration and say complex and precipitate it to be filtered out by pool filter? Wikipedia states that it has strong interaction with melamine, forming insoluble solid. Would this be a safe route to reduce CYA concentration in pool? It should be noted that Sodium bicarb, chlorine, and sodium sulfate are usually also present in pool water as alkalinity and pH stabilizers.

[AWK]

https://patents.google.com/patent/EP2897909A1/en

[pcm81]

Updating this thread to include results from my experience for future readers:
1. Chemical approaches do not seem to exist. At-least not on the scale required for pool use.
2. I was able to reduce CYA from 150ppm to 90ppm using Bio-Active pool stabilizer reducer. This is a powder containing an algae like organism that eats up CYA. Being a living organism it will be killed by chlorine, so it is important to reduce chlorine content with Sodium Thiosulfate to near 0 prior to addition of the Bio-Active product. Over the course of 4 days the CYA ppm dropped from 150 to 90. Algae will grow in the pool due to lack of chlorine, so you should expect pool to turn green.  Bioactive organism and algae then can be killed by addition of liquid chlorine. Significant amount of filtration and possible a flocculant of pool clearer may be required as well.