Lost 10'' over night

[kpe1964]

filter pump turned off by timmer. next morning lost 10'' . Turne off the timmer came home that afternoon lost another 10"- 12", By day three water level down to the last step. Last month found a leak under the skimmer after I dug a 4' x 6' hole under the concrete. Pressured tested intake and return lines, found another leak on the line going to the jets in the steps, capped that line, and now this. The dump line on filter head has a ball valve and works. My theroy is that now that all the water is out of the steps. The steps are trying to float causing the leak. The liner is a little spoungy about 3' from the steps from a small pin hole, but could in know way accodmate the amount of water loss. Does any one have any suggestions?

[ChuckGeo]

Assuming that the water level has dropped below the skimmer, the return fittings and the light and is still dropping, I'd say you have a hole(s) in the liner or a leak in the main drain sump. A liner leak this large should be a sizable hole, maybe 1" in diameter, and may wash out some of the bottom at the location of the leak - look for a wash out under the liner, they can look like a divot in the bottom or slope walls. Also, if you have a ladder make sure it has bumpers in it where it rests against the wall. If the bumpers are missing the legs may have cut holes in the liner.