So I got my Taylor K-2006 kit a couple weeks ago and it's been working great for me. I left for a few days and did an FC test this morning. I got no color change whatsoever when adding the R-0870 powder. Never had this problem before. So I added an amt of chlorine that should have brought the FC up from 0 to about 5 and I STILL got no color change. So I added the same amount again. Same result. My pool now must have a shock level of chlorine in it and the kit is detecting no FC. So I simply mixed some chlorine with tap water at a very high concentrate and tested it....still nothing. What gives? Could my R-0870 in my two week old kit have gone bad? One thing to note is that I recently overshot raising my PH and got it way up somewhere in the 8.2-8.4 range. I don't think this can have an effect on the FC reading and certainly wouldn't explain my problem with the tap water mix.