I'm getting the hang of the test kit and I have a question around the calcium hardness test (and the TA is kind of the same way). When I add the R-0011L and swirl, the sample turns red. I begin adding R-0012 and start counting. At some point the sample turns a light purple almost, but it's definitely not red...or blue for that matter. As I keep dropping, the sample will turn a very light blue and as I continue to add it eventually becomes BLUE BLUE. At what point in this process exactly is "until the color changes from red to blue"?