I have a round gravity feeder suited for 25 birds
I use this 15 lb Galvanized feeder hanging from the ceiling.the crumble doesn’t go through it well enough to keep the bin full.
It's adjustable to 3 positions.
I've used Crumbles for years on the middle position and have been using mini-pellets in the same position for a couple of months.
It's also available in a 30 lb size.
I got it at TSC. GC