I'm using Dichlor-then-bleach for a 430 gallon spa with EOS ozone generator.
Over the course of a week following water change, I added about 5.5 cumulative TBSP of Dichlor. This should have gotten me to just over 20 PPM of CYA.
However, using the 30 mL CYA test from TFTestKits I have the dot...