Interesting CC test result

[donfranko]

I tested my water using the dp powder and when I tested for CC it came up zero, the sample was clear. I left the sample in the tube and 15 – 20 minutes later it was pink. I’m assuming my CC is still zero but wondered if anyone else ever noticed this reaction. Any chemical experts out there than can explain the cause of this?

[DavidD]

I, as well as others have noticed this before. There have been several threads on this in the past, one relatively recently. You are correct, you still have "0" CC's. I believe someone (Evan maybe?) mentioned at one time that he thought the reagent (R0871) was breaking down causing the the CC to become noticeable.

Dave

[waterbear]

The CC test should be read immediately. If you add the potasium iodide reagent and no pink color develops there is no CC. If a pink color develops titrate until the sample turns clear. It is normal for a pink color to develop on standing. Same for the DPD test (comparator). Once the third reagent is added the test needs to be read immediately. Hope this clears this up.