Bill,

Right in this section are several stickied threads on alkalinity and aeration.

The short answer is you are right--you aerate to re-raise pH without increase T/A.

You can aerate by pointing the returns right along the surface.

You can buy a cheap fountain sprayer that screws into the return outlet (they were a sale for $6 or $7 just last Sunday.) This does a FANTASTIC job of aeration.

A gang of 12 year olds works too.