I'm having something rather strange happen with my TF-100 test kit.
I'm doing a bucket test (2gal pool water, 1/4 tsp bleach), and using the FAS/DPD drop test for FC.
I add the powder, then swirl, then add 4 drops of the R-0871 liquid. It neutralizes the pink color.
But then if I wait a minute, the pink color slowly comes back. I can neutralize it again with a couple of drops of the R-0871, but it will come back again.
If I can't even trust my basic FC test, I'm worried. Thank you for helping me figure out what's going on.
(background - I just returned from vacation to no chlorine, and all the CYA gone too; likely converted to ammonia. Algae starting to grow)