Start using some regular bleach or even shock to help the CL move up and calcium hardness to go up slightly. The SWC does not have to be increased, just adding more bleach will save on cell life.

The CYA at 40 ppm could be increased slightly up to 60 ppm.

Use Muriatic acid to keep at 7.2 -7.6 pH and no higher.

Follwing these initial rules will help to start removing the Calcium deposits. If the TA starts to rise start some aeration to help bring it down.

Hope this helps and keep us posted.

Pat