Does cya evaporate?

[mrpoolman]

I know you need to drain water and add fresh water to reduce cya. Does it also go down when water evaporates? On a hot day I lose an inch of water. When I add fresh water am I lowering the cya as if drained and filled? Thanks.

 

[tim5055]

No, the CYA stays in the pool, it does not evaporate. When your poo level goes down due to evaporation the CYA level actually goes up, but it is such a small amount it really can't be seen in the testing.