FAS DPD test

[kerrypope]

What does it mean if I get no color change when adding 1 heaping spoon of 870 powder, then two. No change to pink. This has happened only this last test. Previous test 3 days ago showed up fine.

FC, CC, TC ?
PH 7.8
TA 100
CYA 40

 

[JasonLion]

That means that FC is probably zero. To find out CC you need to continue with the test.