Stabilized chlorine is chlorine normally added to swimming pool water that also contains a stabilizing agent, such as cyanuric acid, designed to slow the destruction of dissolved chlorine in swimming pool water when exposed to UV light (sunlight).
What is Stabilized Chlorine for pools?
Stabilized chlorine is basically chlorine that is guarded from the effect of ultraviolet (UV) radiation. Chlorine is normally very susceptible when it comes to exposure to sunlight radiation, where the UV energy is capable of breaking the bonds between chlorine molecules producing chlorine atoms, which are deactivated as a sanitizer, or simply turned to gas and escape the pool surface. In as little as two hours in full sunlight, an adequately-chlorinated pool can be completely stripped of its much-needed free chlorine.
The most commonly used chlorine stabilizer in swimming pools is cyanuric acid. It normally forms a weak bond with free chlorine in the swimming pool water and therefore protects it from the effect of UV radiation. Indoor pools do not need much cyanuric acid since they are not exposed to solar radiation. Cyanuric acid can greatly reduce the amount of chlorine used in swimming pools if used in the right proportions, reducing the time to add chemicals and the expense of chlorine. Care should be taken to not overuse cyanuric acid, as the level in the pool, denoted as CYA, needs to be monitored.