Mine pumps from a lower pond into a small skippy filter (with a garden hose hooked to the pump) I made. That flows out into an upper pond, which flows back into the lower pond. Very simple, not anything fancy or nice to look at. I've tried lots of plants in the filter to help, but the geese eat them all (even an entire cattail plant). I need to set it up higher somehow so they can't reach it. It works best after it's been running a couple months. But it does eventually start keeping the water pretty clean. At least for 3 geese and 5 ducks! In the skippy filter is just furnace filter material cut into small squares.
Old thread, but was hoping jellybean might see this and provide some pictures.
Doing skippy filter research this weekend and hoping to get started on something soon so the ducks can have more water and not have it like it was this morning after 2.5 days - ew!