I have never added the buffer solution when testing for CH, in fact, I never knew it existed until I read the instructions recently. Is it mandatory? My old test kit (Walmart?) had two vials, A &B, no buffer. I replaced it with Taylor reagents which I think are the same as A & B as they perform the same, but the instructions also include a third vial, the buffer solution which is NaOH. Can I do without this step? The only issue I ever noticed (with both kits) is sometimes if the pH is low the test doesn't work properly. the sample turns yellow instead of pink, however, I have found that if I just leave the sample out for a few minutes it turns pink and then the test works properly, I guess because the ph rises a bit on standing.