The dipper isn't a very accurate measuring device. Sometimes the powder is actually a small chunk or two. Sometimes a little extra powder gets dropped into the test container. And if I use the dipper to stir the mixture, well there is always a little extra on the dipper.Using the small spoon shaped end of the dipper, add one heaping dipper, or two level dippers, of R-0870 and swirl to mix. If the sample turns pink for a moment and then turns clear again, or if it turns brown, add another dipper of R-0870. If the sample remains clear the entire time, your FC level is probably zero, however it is best to verify that with an OTO chlorine test, since the FAS-DPD test is prone to the occasional false zero
Then the instructions say if the sample doesn't turn pink, add another dipper.
So, does it really matter how much R-0870 is added to the sample?
If I didn't put enough in it, will it give me a false low FC reading?
If I put too much, would it give me a false high?