Subtract 1/3 CYA value from TA reading?

[datadr93]

Never did this once

From Taylors website:

Technical FAQs

False-high reading due to cyanuric acid
Cyanuric acid (CYA) titrates as total alkalinity when CYA is greater than 30 ppm. Adjust for this by subtracting 1/3 of your CYA reading from your total alkalinity reading to get the correct alkalinity value. For a more detailed explanation, refer to page 14 in your 2004B booklet.

 

[PoolStored]

Since you are using pool math, don't worry about any adjustments, pool math does that when it calculates CSI. Enter TA as the actual value from your test kit.

 

[ajw22]

TFP recommendations do not use adjusted alkalinity.

Read TA - Further Reading