The Dolphin Sigma states in the manual that it should only be used with a max Chlorine content of 4ppm:
LINK

Looking at the Chlorine/CYA chart 4ppm is really low.
It is below the target level for my pool with CYA of 60.
Thoughts, Comments?
LINK

Looking at the Chlorine/CYA chart 4ppm is really low.
It is below the target level for my pool with CYA of 60.
Thoughts, Comments?