At what pH does CaRx media begin to dissolve?

[cato]

At what pH does CaRx media begin to dissolve?
What are most running their calcium reactors at?

Thanks

[tmz]

CACO3 begins to dissolve at 7.7 depending to some extent on alklinity levels; most run reactors between 6.5 and 6.9.

[cato]

Thanks