Ok, it's been really hot and humid here... 95 to 100 degrees and high heat index the past week. My pool is not screened and gets about 10 hours of full sun a day right now. My pool temp was 90 yesterday afternoon, like bathwater.....
I have seen a loss of 7 in my FC during the day (i turned off my SWG during the day to see what the loss actually was). I do the overnight loss test and no loss and no CC. My numbers:
TA 90 (been getting it down)
pH 7.2 (again, adding MA and aerating to get TA down)
After confirming no overnight loss, I just added 5 lbs of stabilizer to raise the CYA.
I am running my SWG at almost 60% just to keep my FC in a safe range.
Can the sun knock my FC down by 7 during a hot summer day with my CYA at 50?