I'm slowly adding stabilzer to pool to gradually boost cya so as to not go overboard.(Was at 27, now 30, shooting for your rec. of 40 for a 22,500 gal vinly AG) However, the level is creeping up a little too slowly and I've run out of the chems to test already I'm in the process of ordering 'another round' as it were. But, when this new batch arrives, has anyone tried this test using less of the chem required along with the lesser amt of pool water? I understand you need to have enough mixture to properly fill the tube if levels are low, but once you get it to the range you want, can you cut back on the amount you use, and is it just a half/half ratio? At this rate, I'll go broke buying the test kit!!