I always feel it's a possibility in the beginning of the season because I forget how often I have to add water. that said, I have had a leak at my skimmer a couple times. It looked like I may have something open there so I put some pool putty or whatever the pool store told me to use last time. then I filled the pool to a line in the tile. I've lost about an inch of water in 18ish hours. Less than 24 for sure. No one has swam, so zero splash out. My CYA has dropped from tested 70 but then I've added to what should be 80 down to 60. My SWG is still working, so salt hasn't dropped significantly which seems odd.