First I want to say thank you TFP, since switching, last year, to the BBB method and using the TF-100 test kit my pool has truely been trouble free!
I do have a question on testing the TA with the TF-100. I get a distinct color change at 7 drops but it seems to be more purple than red. The 8th drop makes it more redish purple and the 9th drop does not seem to change the color at all. Would you say my TA is 80? That's how I've been calling it but just want to make sure.