Made a feeder out of a square Kitty Litter bucket with 2 3-1/2" street elbows. I ended up cutting the holes small and using my dremel with a cutting wheel, I cut the rest of the way to the size of the elbow. It made tabs all the way around the hole and I simply pushed the elbow in. Perfect friction fit!! Unfortunately, I did it one the 2nd hole.... But I really like the results.
It took the girls about 3 seconds to figure this set up out. Even the ducks!!
Now I need to find a thicker bucket for the waterer. I used another Kitty Litter bucket and I couldn't get a good seal.