If NONE of the fish will eat the AM500, is there any chance that bag has spoiled or developed some mold?
Likewise, quality control is pretty good on animal feeds, but every industrial process has the possibility of a bad batch. Perhaps you got some food from a bad run?
Any pond buddies nearby that would let you borrow a few cups of AM500 to test against your bag?
(Just throwing out ideas, based on what I read on the forum from the people that do comment on their feeding programs.)
