Cyanuric acid is the stabilizer used in pool chlorine, but even it breaks down relatively quickly in the environment. https://pubmed.ncbi.nlm.nih.gov/4451360/ h

Cyanuric acid is the stabilizer used in pool chlorine, but even it breaks down relatively quickly in the environment. https://pubmed.ncbi.nlm.nih.gov/4451360/ https://pubmed.ncbi.nlm.nih.gov/4451360/ Also if chlorine is stabilized by cyanuric acid, it is no longer active in the environment - basically the cyanuric acid locks up the chlorine in an equilibrium so that it slow releases, which is why it's widely used in outdoor pools. Otherwise UV exposure would cause the chlorine to offgas rapidly and you'd need to add chlorine every hour or so during the day, which is obviously effort and cost prohibitive.