Lively,
Great! Definitely get the CYA up asap. Are you using granules or liquid? If granules squeeze the sock a couple times each day. Even with that it will take 2 days. Newdude is correct that your FC loss is increased with higher levels. If it were me with still some lingering question about your cell I would stabilize with liquid chlorine at a level well above target say FC 10-12. Then once you know how much daytime demand you have you can run it to produce that amount. I suspect your cell is fine since you had one night where it looks like it produced exactly the right amount. But if for some reason it is not working you won't drop too low. I'm suggesting this because I know it's critical for your wife to have access to the pool.
So glad things are looking up!
Chris
Chris, this was running through my head as well. Previously I used trichlor to raise cya, so I have to go buy some. I'm going to get the liquid to make it easier.
I'm going to allow drift to 12FC, while allowing pump run time to be 12hrs and will cut on the SWG at ~12. If I drift back up, adjust slowly until I find stability at the 6-8 mark.
This will help allow for rain compensation etc. At least that's my theory.
I think the cell is fine too, who knows what was eating the chlorine, but it is obvious I didn't have enough, granted the water was clear. Not as soft, but clear as shown before.
It's beyond my understanding, but at least now I have a good starting point reference and can keep updating here to gain the knowledge to stabilize. Like my reef tank, stability is key, which is why I went with SWG also, nothing like less swings to aid stability.
Thanks to everyone again so far, here's to the next critical few days.