You are pulling your hair out trying to figure out why your pond is still losing water. Do you have a fountain in the pond? If so, make sure the fountain is not too close to the edge and water is splashing out. Check your waterfall as well. If water is splashing on the rocks near the edge of the waterfall, it is splashing out. Falling water must have an area twice as wide as the water is high for the water to stay contained. So if your waterfall or fountain is pumping water 2 feet above the pond, the pond must have 4' of surface for it to fall into.
One more thing: If you have a fountain with some sort of nozzle or a spitter that sends water far in the air, the wind can blow the water out of the pond. Watch your pond water level when the wind is blowing. You might want to turn off your pump if it's windy.
The holes in a nozzle can get clogged up and pretty soon you have one thin stream of water shooting out. It is hard to see because it is so thin. Check it. You may wish to remove the nozzle completely. Or clean it lots and lots. With a toothpick. And a brush. In the water. With your boots on. Frustrating.