For the past several years, my FC numbers have always been within normal limits. Two months ago, for some reason, my FC jumped up to 15+! I might have put too much liquid chlorine but I have a hard time thinking I poured that much to make my FC jump this high. (Only have 6000 gal)The FC is down to 10 but its been a slow process. My water is in the 60's. Could my Taylor DPD powder or R-0871 be contaminated for some reason? Could my vial be contaminated? I tried a different DPD powder container and R-0871 but got the same results. For the past two months, I went to Leslie's twice to see their FC results and both tests were much lower, 8 and, yesterday, 5. I never trust Lesie's test results but in the past, when I did check, their results were never off by this much. Maybe I did pour too much Liquid chlorine??? And just move on!