Ront,
My cya reading with colorQ has not gone above 9 where my cya should be about 50. According to laMotte CYA is temperature dependent so you can not just add a number to what you get from the colorQ to be accurate since the water temperature varies with the season . In order to get this machine to work right they should take into account other factors in addition to color and the machine needs to be more sophisticated and probably more expensive. I for one would have paid another $50 for a more reliable machine. I guess if you think of the machine as a test fro cl, alk, ph and ch only it is not bad.
Regards

Amir