I'm getting FC #'s all over the map. The directions call for "two dippers" of the R-0870 DPD powder. This seems very non-repeatable to me. Sometimes the crystals clump together, sometimes a few stick to the dipper. Also there's no compensation for 10 ml vs 25 mL sample? How important is the amount of crystals to the test results? Or can I just add any amount that turns the sample pink?