Well can't explain that only know what tests say and ph meter and I calibrated it to make sure it was reading right tried to get a pic of it on ph meter but it never showed up in pic .I wonder if when I looked at the water meter I read that wrong, not sure ,I usually double check things but I did not that time .I also added koi clay to help keep fish from stressing and to clean the water because of moving plants out of pond .Well I took every thing apart at 4 am and redid everything and added water at that time and thought I lost half inch of turns out it was a quarter inch of water and it is 7:02 PM now , so far sounds good ,measure stick moved sideways and it looked like more .So I put a screw in it to hold it in place new one is coming monday .I pulled a lot of plants and even called firestone and they said if it was the new liner they would replace it with no charge ,amazed me they would do that .Dr foster and Smith where I bought the liner backed me up and said if it was the liner they would have no problem replacing it and told both I was trying to find the source of the leak .Funny thing is under both liners in waterfalls it was dry as could be so not sure where the water went .Since there is a double wall on my pond I looked between the double wall closely but nothing .There is about 8 inch's between the walls and it has sand in there with a layer of rock on top .