The funny thing is, their test was telling me NOT to spend any money! But when I insisted, he did try to sell me something almost twice as expensive. I checked the pool (visually, not the levels) at nap, and about half of the CYA was gone, I will continue to monitor it though. I don't plan to use the trichlor throughout the swim season. I might use up what I have, but I plan to use bleach as my main source of chlorine. I just have the tricholor from last year when I was a dummy and did everything the pool store told me. Thanks