FAS-DPD testing during SLAM

[flipr]

Is it normal for the testing never to get to really clear? Seems at higher FC levels the best I get is a grey solution with bits of black floating in my 10 ml sample. Definitely starts red, but never goes clear. this doesn't happen when I was testing at levels FC 3-5 ppm, just during slam. Using speedstir, also.
Never finding any CC's either in testing, adding 5 drops to the grey solution doesn't turn red at all.

Are my results normal?

Thanks much

 

[Mr Bruce]

Yes, it's normal. As soon as there is no more pink you are done.

 

[flipr]

Thanks for confirming I was doing it right.