So after spending the last two years bringing my CYA level down from the obscene levels, having been "pool stored", I've successfully lowered it to about 40 this season. In the CYA section of the ABCs of Pool Water Chemistry, it states "If you don't have a SWG or problems from extremely high amounts of sunlight, CYA is typically kept between 30 and 50. If you have a SWG or very high levels of direct sunlight, CYA is typically kept between 70 and 80." Right now I have almost 10 hours of direct sunlight, even longer in July. I am wondering if I should slowly raise my CYA back up to 70. For this season, a daily liquid bleach (12.5%) add for me has been circa 10 cups. I've been targeting FC of 8, rather than 5, as I've found that 5 would lower too quickly for me on the following day, I would have some CC and would then have to shock. (Happened twice this summer, if that information is helpful.)
By no means an urgent question, but given the global nature of this site, I'm not sure if my hours of direct sunlight are high enough to warrant adjusting my CYA target.
Thanks for all the help!