I have a pond as well. We manage the number of fish in it. We take out the fish that are between 15 and 18 inches and put them in a bigger pond on my neighbor's property. as a result we have a large number of small fish that are easy and fun to catch. We also have a couple of fish that are 20 and 24 inches long. The bigger fish have plenty of food to survive and maintain and the smaller ones grow, spawn and eventually get culled. Too many fish spoils the pond.