I chlorinate with bleach, not trichlor. My CYA has run about 40 all summer. Today I test it (new reagent) and find it to be almost undetectable. I went to the Pool Store to verify, and they confirm
Another barely related question: I have done some of the reading on the loss of strength over time of chlorine. Is that a measurable loss or just an effective loss. That is, if you use old, weak bleach, will the FC reflect that or will it still rise with the addition of that weak bleach. Considering that in relation to my trichlor, will it be effective or just trash it?
Results mine theirs
FC 4.5 5
CC 0.5 0 (according to my tests, I can almost NEVER get this to zero even while shocking)
pH 7.8 6.8 (Added MA before taking store sample and not enough time to mix)
TA 60 50
CH 270 150
CYA <20 20
T 76 degrees
Where did the CYA go? Had some rain recently, but not too much. I don't backwash.
Moving forward, should I just start using the trichlor that has been on my patio for the past 4 months, use stabilizer, or the "conditioner" they wanted to sell me.