Years ago I had 2 large mouth bass and 2 blue gills, all about 4", in a tank. Talk about cleaning up a bunch of feeder fish fast!
At the time, we had several large cattle tanks stocked with guppies/mosquito fish, so I could drop 20-30 in the tank any time I wanted. They were all gone in seconds.
I gave one blue gill away early on. One bass died early. One bass and 1 blue gill made it to 8.5 " long before the bass died and I gave the blue gill away. Wish I would have kept the blue gill.