Yesterday was full test day. In the on-season, I perform my full testing approx. 1x/mo. At 0745, here were my results:
CH 1100 (yes, I know high, but that is not the topic of this thread. I am managing it and using Pool Math to keep h2o balanced)
water temp = 82
I added 28 oz chlorine (I use 12.5%) and 37 oz MA (I use 14.5%). When my CYA was 50, on the days I added chlorine I would always add to the upper limit of the recommendation. So, I added 28 oz chlorine to bring up my FC to 7.
I am curious how my CYA could have dropped to 40. For approx. a year since I have been managing my water and using the TF-100, it has been 50. I did a partial drain/fill last year around this time to bring it down to 50. FWIW, if it may have affected things, I recently began using a 8 mil solar cover. Is a CYA of 40 okay? I have read so many threads on here that have discussions about different CYA levels. It appears there is no clear cut answer. My pool generally gets sun for approx. 8 hr/day +/-.
Is there a recommended level given my details?
Tx for any help.