You really need to use the proper reagent . Taylor makes several that are used with different comparators. I will bet that the reagent you bought is R-0004. the one you need is R-0014. R-0004 is meant to be used with a 45 ml water sample in a large comparator tube like the one in the Taylor k-2005 and K-2006. R-0014 is meant for small comparator tubes like the one in your kit.