Thanks Pat. A few follow ups/responses to your queries.

1. During the superchlorination, I unplugged the SWG and used bleach. When I started to read levels approaching 5ppm, I plugged it back in. Reading Ben's best guess chart on CYA, 5ppm seemed to be a good target not knowing what my CYA was accurately. Seems like 5ppm will be decent for CYA levels from 10 to 90 (i.e. within min/max range for those CYA levels).

I plugged cell back in a few days back when TC seemed to be around 6ppm. I has dropped a little to 5 or so (again, these are kind of rough numbers using approximation through dilution). But I think we are pretty close on the level out of the cell for now. It is at level 2, 50%...seems to shift between 50 to 70%. I also need Ben's test for salt calibration, but whatever it is at, it seems like I am close to getting the near optimal output level.

2. I am diluting the acid in a 1 1/2 qt container with water, and then broadcasting over the deep end to try and avoid aeration. I have two very active returns in the shallow end (one pointing somewhat upwards) and then another in the deep, but it is pretty deep and doesn't seem to be affecting the surface in any way. I do have a spa with a spillover. Any advice to avoid any inadvertant aeration? Put the return valve fully to the pool with nothing going to the spa (seems to create a problem of lack of circulation/chlorination to the spa)?

3. Thanks for the advice on CYA. As I said, once I get Ben's kit, I can get a better idea of where I stand. Anyone have a recent delivery that can tell me their waiting time?