Since chlorine is not as effective a sanitizer the higher the CYA levels, you need to add more chlorine, ala Ben's "Best Guess" table.

Since chlorine is not as effective a sanitizer at higher PH levels, does there need to be a "best guess" table for PH as well?

I wonder if the pools that run high PH in Ben's "high PH" article run chlorine at higher levels because of this?

I also wonder if pools running high CYA AND high PH get a double whammy on chlorine effectiveness?