I'm impressed with the short delivery time and kit operation was a no brainer! I'm a happy camper with your product.
1. The calcium hardness test formed a noticeable amount of precipitate when I began adding reagent R-0012. If I recall accurately, the precipitate resolved by the time that blue coloration became apparent. I also had the impression that the particle size varied. I'm curious about the chemistry behind the precipitation and it's resolution.
2. About Color Change. Color changes are easily perceived in each of the drop tests, but additional drops seem to perhaps linearly increase the intensity of final color. I was not sure what to use as a visual endpoint. As an example, stage one of the CH test appears to move through an early pink to a deep red color as R-0011L drops are added and stage two moved through quite a range of blue as drops of R-0012. How do youvisually judge the colorimetric endpoints when you personally test water? Have you even done any "smackdown" testing wherein you and several others pros that you know tested the same sample at the same time using your test kit without discussing color change endpoint ahead of time?
3. Can I assume that the materials included in the blue box for "daily testing" provide an accurate enough assessment of pH to satisfy professional pool keepers?