Okay, so I am new to testing my own water. I have two tests kits, both Taylor brand. One is an OTO kit that tests total chlorine, bromine, and Ph. The other is a K-1001 DPD that tests free chlorine, bromine, and Ph. We tested out water at a pool supply store on Friday and it said our total chlorine was at 10 and the free chlorine was at 10 as well. We tested it with the OTO kit for total chlorine the next day, Saturday, and it was at about 5 ppm. The DPD kit was at about 5ppm as well. We had several people in the pool on Saturday and Sunday. Now it's Monday and the total chlorine reads about 1ppm and the free chlorine is basically completely clear, or zero?! Is this normal? How can a pool go from 10ppm free chlorine on Friday to 0ppm on Monday?
ETA: we did add a little acid in Friday because the Ph was also really high (8) and we brought it down to 7.2. But the Chlorine levels were still high on Saturday, as mentioned above.