This is my first summer with a pool and the TFP method has been wonderful - giving me a beautifully clear pool all summer. At the beginning of the summer, I had a high CYA level and had to replace water to bring it down to 40. I checked my CYA level for the first time in a little over a month today and it is below 30. I completely filled the tube and could still see the black dot. I am out of R-0013 reagent and just reordered a 16oz bottle, so I'll have to wait about a week or so before I can check it again.
First, I'm not real sure how this could have happened since the only way to lower CYA is to replace water. I do get a lot of rain in my area - could that explain it? It's also possible I simply messed up the test, but again I can't confirm it at the moment.
Second, should I even bother raising CYA? I've been maintaining my FC level at 5 ppm, but I only lose 1-2 ppm a day. I very rarely lose more than 2 ppm in a day. If that rate of decline stays the same, do you think it's even worth bothering raising CYA?
I do have some 1-inch trichlor tabs left over from the previous owner I can put in the skimmer basket, so it will be easy enough to raise the CYA.
Thanks for your help!
EDIT:
I thought I should add my full test results:
FC - 3.5 (just raised to 5)
CC - 0
PH - 7.8
TA - 70
CH - 120
CYA - <30
I may test CH again in the morning as well. Borjis's comment below helped me realize that if CYA has fallen I should expect to see CH fall too. This test would indicate it hadn't changed, but I had difficulty with that test today as the sample turned from a very faint red to a very faint blue. It was so faint I may have misinterpreted when it turned from red to clear to blue.
First, I'm not real sure how this could have happened since the only way to lower CYA is to replace water. I do get a lot of rain in my area - could that explain it? It's also possible I simply messed up the test, but again I can't confirm it at the moment.
Second, should I even bother raising CYA? I've been maintaining my FC level at 5 ppm, but I only lose 1-2 ppm a day. I very rarely lose more than 2 ppm in a day. If that rate of decline stays the same, do you think it's even worth bothering raising CYA?
I do have some 1-inch trichlor tabs left over from the previous owner I can put in the skimmer basket, so it will be easy enough to raise the CYA.
Thanks for your help!
EDIT:
I thought I should add my full test results:
FC - 3.5 (just raised to 5)
CC - 0
PH - 7.8
TA - 70
CH - 120
CYA - <30
I may test CH again in the morning as well. Borjis's comment below helped me realize that if CYA has fallen I should expect to see CH fall too. This test would indicate it hadn't changed, but I had difficulty with that test today as the sample turned from a very faint red to a very faint blue. It was so faint I may have misinterpreted when it turned from red to clear to blue.
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