Like you, my pool builder gave me a test kit (I'm sure he really didn't "give" it away as I probably paid $100 hidden in the price of the pool) that used 4 drops for PH and chlorine. Like you, I assume it was a concentration thing or something. As far as the chlorine test, I went through the same thing when I started reading post here. "How the heck are these guys coming up with al these high chlorine numbers?" Once I received Ben's kit, I found out that the 4ppm of chlorine I had was actually FC <3ppm and CC >1ppm! Boy was I headed for trouble and the pool was only a few months old. Ben's kit seamed a little pricey to me at first but once you look around at say a Taylor kit that will test for the same things it really is a deal. Knowing what I know now, I wouldn't hesitate spending the bucks all over again, even if the price were doubled. I must say, after looking at your great pictures a week or so ago, your water looks really good to have been guessing, which no offense intended, is what anyone does with only an OTO test for chlorine. Ben apparently is behind in shipping his kits but if I were you, I'd go ahead and order one soon.

Dave