Our fishes are getting so big. We have a 20 gallon aquarium. We started out with five gold fish, one cleaner. One day when we were fishing my son scooped up in our minnow net a small cat fish. The cat fish is big enough now where the fish food is not satisfying. We threw a crab in there and the next morning there was no crab anymore. His belly was full. Now everyday my son is in search of small worms so the cat fish doesn't eat our gold fish that are twice his size.