I have about 30-35 turtles that are ready when my feeder goes off... they consume a lot of feed, my BG just pick one at a time off while the turtles just cruise the surface slurping up piece after piece.
No worries about too much feed in the pond, those turtles will eat until it's all gone.
Between the mallard and her 4 now about grown ducklings my BG don't have much of a chance to eat...