I bought a bunch of these feeders from Tractor Supply
They are really supposed to be used with a mason jar as the feed hopper
But what ends up happening is the feed just free flows when the birds toss it out. The birds will waste an entire quart mason jar of food in a couple of hours. They only eat a little and toss the rest out.
So what I did was pull the mason jar attachment off of the feeder. It's only attached by folding a lip of the galvanized metal onto itself. I used a screw driver to unfold the metal and remove the jar attachment part.
Then I purchased a PVC reducer coupling. Mine were 3" reduced to 2".
I used a sharpie marker to trace around the reducer and onto the galvanized feeder lid. Then I used a metal saw blade and trimmed the hole large enough to accept the PVC reducer. From that point I added a 3" PVC pipe as a hopper. Make it as tall as you want.
The key is to seat the PVC reducer far enough into the feeder so only about a 1/2 " of space is available underneath it. This slows down how fast the feed dispenses and lowers the level of the feed in the feeder. The birds have to stick more of their head into the feeder and they can't beak it all out.
Simple redneck solution to a feed waste problem.
Chicken-Farmer