Help, my pond is leaking

I had to share my flower garden as of 10 minutes ago. The New Orleans spring garden makes it allmost worth it to live here.

Now on to the leaking pond:

Chances are, if your water level is dropping fast, you do not have a hole in your liner, so relax. Now that you are relaxed, here's how to find that leak. Turn your pump off. Fill your pond up. Tomorrow morning have a look at it. If the water level is where you left it, the water is falling off your waterfall and ending up on the ground, not in your pond. Your rocks have settled or some critter has knocked them around. Turn the pump on again and you will find that leak right away. Put the waterfall rocks right and your leaking problems are over. Now wasn't that easy? And you saved the cost of a trouble call to a professional.

Repairing a preformed pond

Usually when a preformed pond springs a leak, it is where the pond has ledges. We tend to step on the ledge when we get in the pond and because we have not seated it properly in the ground (almost an impossibility), it cracks. Now what?
I know of no way to patch a preformed hard plastic pond. I have heard of folks using Bondo, but have not seen it first hand. Because they are impossible to patch and crack so readily, I recommend against using them. If you wish to use a preformed pond, go to a feed store and buy a horse feeding trough. Rubbermaid makes them, they have a flat bottom, no ledges, are virtually indestructible and are much much cheaper than the preformed pond you find at the big box store.