So I've read a lot of threads about this and it seems that the general consensus is that you can add too little powder but adding too much does not affect your results. When I follow the directions from the TF 100 kit and use 1 heaping scoop, my FC reading is always lower than if I add two scoops. I also noticed that 1 heaping scoop always produced a light shade of pink (while there were still some undissolved particles) whereas 2 scoops always produced a much darker and vibrant shade of pink (with undissolved particles). So my question is which method is correct? should I always add enough to get the vibrant pink color or just 1 heaping scoop?
Also, does it affect the test if I stir the solution with the scooper? Sometimes the DPD powder clumps up after adding it into the water so I just stir it around a bit with the little scooper to make sure it gets dissolved. Thanks.
I tried using some test strips that I have from my hot tub and the FC reading is always 0. Should I just disregard the accuracy of those strips?