Thanks Michael,
I understand about the cya. There was discussion in the "old" forum that a vinyl liner could take 15 ppm, and I did go that high last Spring in an effort to speed up clearing the water. I know liners do fade over time, but mine was only 2 years old, which I thought was pretty new.

Anyway, I have a new liner, (due to disastrous encounter late last summer with an umbrella during a storm), and I'm going to try to be more conservative with the chlorine. I'm going to try the 60-80 cya and 1-3 ppm cl called for in the Aquarite manual.

I am a little nervous about that because according to the "best guess" chart, 60-80 cya requires a minimum FC level of 5ppm. Maybe the numbers are different with the SWC (I hope).
PAT