well, according to that Australian reference chlorine efficiency at pH = 8 is 3%, now considering CYA allows chlorine level to drop by only 30% (compared to what it is at pH=7.5), it still will indicate that at pH=8, we have only 9% effective chlorine? Am I missing something? One of the earlier posts says pH reading will be erroneous for high FC. But both the pool store analysis (when FC was 5) and my analysis when FC was 9 gave the same high pH >8. What is the threshold value for FC for correct pH reading with a Taylor K2006 kit?