First, my current numbers are:
FC = 25.5 (had my SWG at 60-80% while it was in the 90's which kept it in the teens, now its cloudy and in the 70's-80's. Need to decrease SWG %)
CC = 0
Calcium = 275-300
PH = 7.4 (but rises quickly quite often)
CYA = tested 4 times different times and different samples all when sunny out at 50ppm (background: was at 70ppm about 2 weeks ago and I decided to increase it to 80ppm by adding a little CYA. Somehow it dropped to 50!!??!)
TA = 70
My CYA has been in the 70-80 range since June. I test weekly.
Why would CYA drop like that in a short amount of time especially after adding more CYA 2 weeks ago to raise it?? Doesn't make sense, unless it is due to high FC.
Help please. Thx.