CYA Prevention of Vinyl Liner Wrinkling

[chem geek]

The technical bulletin Formation of Wrinkles in Installed Swimming Pool Liners refers to studies made by FMC and Union Carbide showing that though low pH is more detrimental to vinyl liners than other factors, that CYA can help prevent wrinkles as well. This may be due to the lower active chlorine level when CYA is present as well as CYA's pH buffering capability. For the brominated pools, the CYA shouldn't be lowering the active bromine level, but would still have some pH buffering capability. There might be some other chemistry going on more directly with CYA and vinyl as well.

Yet one more reason to have some CYA in the water even for indoor vinyl pools.

 

[duraleigh]

chem geek,

I am in awe of your ability to research and share the very helpful things you post. I find this one to be one of the most interesting in a while and written even so I can understand it! Kudos!

 

[Glock30]

chem geek,
Thanks for this post as it applies directly to my pool.

Asking for my Mother In Law (who is awesome by the way), does CYA protect bromine the way it does chlorine?

Thanks

 

[JasonLion]

No, bromine can not be stabilized against sunlight. Bromine isn't as sensitive to sunlight as chlorine to begin with, but you are stuck with the sensitivity it does have. You can put CYA in a bromine pool, though other than this wrinkle issue there isn't any point as it won't have any effect on the bromine.

 

[chem geek]

If you have a higher CYA level and a deeper pool, then there can be some protection from the UV in sunlight at lower depths by CYA directly shielding the UV even though it doesn't bind to bromine. This is the effect we see with chlorine and CYA where even at the same FC/CYA ratio, so same active chlorine level, the chlorine protection increases at higher CYA levels, especially as one gets closer to 80 ppm. So this same effect should show up with bromine as well, but it's a relatively minor effect compared to chlorine binding to CYA.