Pond Boss Forums GENERAL QUESTIONS Help Large Carps are dying in pond. Anything I can do?

Since the carp are the largest fish in the pond, they could possibly all have died at the same time from a low O2 event and you are just seeing them now. Since the bass and bluegill are smaller, even though they need a bit more O2 to stay alive, being much smaller they might have survived where the larger fish didn't.