Quote Originally Posted by mas985
Here is the CYA article about plaster and CYA:

http://findarticles.com/p/articles/m...4/ai_n15932555

Although this probably applys more to very high CYA, this was why I was reluctant to go to higher CYA levels. I may end up going a bit higher anyway.
The sudy was done by ARCH chemicals! These are the same people who put copper into trichlor pucks. I am sure they are talking about CYA levels well above 100 ppm! There is also evidence that sulfates from using dry acid can affect the plaster so there can be multiple causes for damage to the plaster finish. The article did state that ARCH chemical recommeded switching between trichlor and other forms of chlorine to keep stabilzier levels from going too high. Does this mean that they are starting to read the Pool Forum? Seem like THAT piece of advice has been given on here for a very long time!