I promise some pictures of my feeder awhile back, well here it is...
This tub will hold a full 100 lbs of feed, and has 8 feeding ports, with the cinder block 'step' on the two short sides, so that the bantams and young birds can get up higher it works for all the chickens and guineas... My peafowl refuse to use it so they get a traditional feeder up high, not that bad since the peas don't throw food around like the others and being up high the others don't use that feeder too often...
I used the drainage street 90s (from post 3) I cut off of the flange (as in post 3) and drilled the holes with a hole saw, the bottom of the elbow is about 3/4" off the bottom of bin... The drilled holes were about 1/8" too small so I went around with a heat gun and warmed the edge of the holes on the tub and then pressed the elbows in, once cooled they are held firmly, so no other securing method was needed...