Anth what size BG were stocked in your pond? They can't eat if they can't fit the pellet in their gape. If you stocked 3-4" BG you're going to need a small pellet - something AM 400 sized.
I think you are right, TJ: Size matters! I had a few hundred 4 to 5 inch CNBG stocked, but thousands of smaller ones. Probably should put up another feeder with AM 400 and see if it makes a difference.
Also have over 100 pounds of FHM, but they are so small I doubt they can do much with any of the feed until it softens and sinks.