My parents have a Koi pond and I rig up a single brown corkie on the mainline, and they will actually fight with just a corkie in their mouth. When they get tired, they just spit it out, and the next one comes up and grabs it.
But my friend has a spring fed pond, that is literally a big hole that a previous owner had dug in the ground. The koffer dammed it up, and created a small one acre-ish pond. It is full of Rainbow, and Kamloops too I believe...It has 15 or 16 Trout over 24" and a whole bunch in the 10- 18 range, and the Bluegill look like a short stack:shock: on its side, with a tail of course. Used to have one Bass in the 4-5 pound neighborhood, but a beaver may have gobbled it. Ponds are great fun and can be very entertaining.