Having read about this "True Total Alkalinity Reading" value and it's formula -> TA - (CYA/3), should I consider it with my water tests?
In the Pool School Recommended levels for Plaster (with Bleach), TA should be 70-90+ ppm. But if I pay attention to this "True Total Alkalinity" formula, and if my CYA is about 30 ppm I end with some value that is almost always less from just reading the TA results from the TF-100 test kit.
For example:
From TF-100 test kit reading: TA = 100 ppm
From "True Total Alkalinity" formula -> TA - (CYA/3):
> = 100 - (30/3)
> = 90 ppm
So, is my TF-100 test kit's TA reading of 100 ppm good enough because if plug it into "True Total Alkalinity" formula it equals to 90 ppm? Or should I discard this "True Total Alkalinity" formula and only pay attention to my TF-100 test kits, TA reading alone thus my TA still needs to be dropped by 10 ppm?
In the Pool School Recommended levels for Plaster (with Bleach), TA should be 70-90+ ppm. But if I pay attention to this "True Total Alkalinity" formula, and if my CYA is about 30 ppm I end with some value that is almost always less from just reading the TA results from the TF-100 test kit.
For example:
From TF-100 test kit reading: TA = 100 ppm
From "True Total Alkalinity" formula -> TA - (CYA/3):
> = 100 - (30/3)
> = 90 ppm
So, is my TF-100 test kit's TA reading of 100 ppm good enough because if plug it into "True Total Alkalinity" formula it equals to 90 ppm? Or should I discard this "True Total Alkalinity" formula and only pay attention to my TF-100 test kits, TA reading alone thus my TA still needs to be dropped by 10 ppm?