When my dad owned my 2.5 acre pond many years ago, it didn't have bluegill but was over populated with stunted large mouth bass and many green sunfish.of all sizes. I bucket stocked adult bluegill into it. Probably about 40 of them, and that's all it needed to kick start the change. Within about three years, the bluegill population overtook the green sunfish and the bass size was much more distributed than a bunch of 10 inch overly hungry fish. It got to the point where the bluegill we were catching far outnumbered the green sunfish.