cya levels

[cvaparo]

What is the purpose of cya in pool water?

 

[Cm_ls1]

CYA is a chemical that acts as a stabiliser in swimming pools and helps to protect chlorine from breakdown due to ultraviolet light from the sun's rays.

 

[cvaparo]

Thank you , so if my spa is indoors is there a need to have any?

 

[JasonLion]

CYA does several things, slowing breakdown from sunlight is the main one, but there is another issue with spas.

It is good to have low levels of CYA (around 20 ppm) in a spa to help buffer the required chlorine levels. Fairly large amounts of chlorine are required in a spa because there is a relatively high ratio of sweat to water. CYA slows down the action of chlorine, steering it away form producing some of the slightly harmful breakdown products, and more towards the safer breakdown products. It also increases swimsuit lifetime (if you wear swimsuits).

 

[chem geek]

The chlorine will also outgas more slowly and degrade hot tub covers more slowly. Basically, CYA moderates chlorine's strength which would otherwise be too strong.