I wonder what Taylor's TA test actually measures. It can't be the actual amount of the bicarbonate anion, because Taylor Tech warns that you have to account for the "alkalinity" contribution of CYA.
Therefore, the TA must be related somehow to the buffering capacity of the dissolved species which serve as buffers.
I read here and in the sister site that Borax actually serves as a buffer too. Does it also contribute to the measured TA?