If FC jumped that high, it means that either a) your pool is not as big as you think or b) the chlorine is stronger than you think. Is 5.25% what they sell where you live? In the US, Chlorox is 8.25%. The difference in strength would account for FC target of 12 or so becoming 21.PH= 8.2 (put in pool math m acid and in an hour it had gone down to 7.2.)
FC= 1
CC= 0.5
TA= 75
CYA 38
So then put in pool math 5.25% chlorine. Tested an hour later and FC was 22, way above the 15 level I was aiming at.
Tested after three hours and the FC is still at 21.
What am I doing wrong?
Probably not a bad one at all. Done is done, anyway.Have I made a mistake putting in more m acid?