Does aeration lower your FC quickly? I was at 7.5 this morning, and left the aerator on all day and came home to FC=1. I figured it did, but that seemed like a huge drop.
I am adding to keep FC at 3-4, while waiting for pH to go back up so I can do another TA drop, and the CYA is simmering in the skimmer. Lots at work for me! Happy results: my TA is at 120 where it was at 200+.