Mmm, thanks for that. I was having a wacky idea about if it was possible to develop a modified TA test to measure the difference in TA caused by the cyanurate ions being taken out of the equation in affecting TA. At pH 8 the correction factor is .36 caused by CYA, so at high CYA's I thought it might be measurable, leading to a drop based CYA test. Raising the pH to 8 would negate the buffer so that screws it!
As an aside, I've subsequently seen TA correction figures for 30-50ppm CYA at various pH values. I assume this breaks down at high CYA levels otherwise members would be reporting proportionately high TA's and this doesn't seem to be the case. Why is that?
Thanks again, Mike