If I am not mistaken the Leslie's kit is a rebranded Taylor kit. If this is true you first add 20 drops of calcium buffer, then 5 drops of indicator (which is blue in color but turns pink if hardness is present) then titrate drop by drop until the color changes to blue. If the Indicator stays blue when you add it then there is not CH present. If this is not the kit you have I am really not sure.