My CYA has declined below 30 over the past week or so. I thought I was around 35 last weekend, but I guess the rain and filter cleaning took its toll. Anyway, I seem to have no problem holding chlorine, even on sunny days. Is there a need for me to boost the CYA to 30? I understand that I may have to do some guesstimating in terms of recommended FC levels, although I tend to shoot for the high end of the range. And if I had to shock, I could overshoot a little and assume a CYA of 30. I know recommended levels are 30-50, but if I can maintain chlorine in sunlight, why not go a little lower?