Richard, I recall reading a thread at poolsolutions last year where you showed a chart illustrating the majority of chlorine protection is obtained at 20 ppm, with minimal additional protection as CYA rises. Since then I've maintained my CYA at about 25, and keep my FC in the corresponding range per the best guess chart. My pool uses about 2 ppm of chlorine daily, get's probably 75% full sun daily, and is not covered.
I was reading some at pool solutions in the PH rising thread there, and Richard said he was rethinking using a minimum CYA level. I'd like to hear what your current thoughts are, and if possible, I'd be interested in increasing my CYA if it will allow me to reduce my bleach consumption. I manually add at night.
One thing I do like about my current approach is the ability to use the OTO test without dillution. I assume a higher CYA still means a higher FC?