Good Calcium hardness number?

[waterbear]

Normally I am fighting a pH that is lowering.

Are you by any chance using tabs in a feeder or floater? Normal tendency for a pool with a TA of 110 ppm would be rising pH unless a stabilized form of chlorine (trichlor tabs or dichlor), or other acidic oxidiers (MPS-non chlorine shock or bromine tablets) are being used. If you are using bleach or liquid chloirne (sodium hypochlorite), cal hypo (calcium hypochlorite), or lithium hypochlorite for your chlorine source then you would see a rising pH.