OK, here's some oddness.
I got my SpeedStir, ran through all the mix tests. FC+CC+TA+CH
Here are my test results.
The weird part is my CH, it tested at 250 mixing by hand, using a 10ml sample, as opposed to the 25ml sample.
That's 10drops X 25 = 250
Even minus 25% accuracy, that's 187.5ppm, much higher still.
When I tested CH by hand, using Richard320's recommendation here.
I had nice vivid colors, when it went from red/pink to purple, then to blue, each color was really dark when done by hand, save for the blue endpoint color, this was light and as I added more drops it got darker & darker till it stopped and that was my number minus any that didn't change it.
Using the speed stir, all the colors are a lot lighter and I never got that vivid blue, just an aquamarine blue, added about 10+ drops over and didn't darken or change.
Did the test 2x and got the same result.
I'd test it again by hand to compare, but there's not very much of the 1st 2 reagents. So I refrained.
I trust the speed stir, but just curious.
So is testing by hand that far off?