I have a question regarding CYA level and FC. My pool is in direct sunlight for most of the day. I have opened the pool with success thanks to this site. My CYA is around 45. (I say around, because I'm not sure when you actually claim the black dot is no longer visible. It gets very faint at 45ish, but I can still barely see it if I squint very hard and focus on it from the beginning. If I have my wife look at it at 45 but not focus on it while filling the tube, she can not see it at 45.)
Anyway, my FC will typically fall about 5 or 6 during a full day of sunlight. This is with good numbers on everything else using the TF 100 kit. MY CC is 0. Is this much of a fall in FC typical, or should I consider a higher CYA level? I'm nervous on raising my CYA level due to the cautions I've read hear about issues with a CYA level too high.