One potential 'mistake' I may have made with Lee's pond is perhaps stocking too many fish (non-fatheads) over the course of a year.
This was because we had a fish-kill of adult Bluegill and some SMB from Hartleys, and the fact that I wasn't seeing any fish visually, or hitting feed like they used to.
So, the massive population of fatheads consumed may have been spread across too many predator fish.
Still a ton of speculation....