@Rob1 , thanks for taking the time to respond.
I haven’t added anything to the tap water, just to the Ashbeck.
@LMSC According to the kit I have the sample size should be 10ml but I’ve used 20ml to try and get a more accurate reading.
I’ll run both tests again tomorrow and pay particular attention to the moment I see any colour change. And be sure to drip vertically.
My scales display in 0.01g increments but doesn’t say how accurate they are.