when I was a kid I had a bullhead for several years, he was about 14" long and had him in a 55 gallon tank. I had a similar setup with some native minnows in a 10 gallon tank. will have to see if I can find any pics of my folks old aquarium. we had always had BIG fish when I was a kid, had a tiger shovel-nose catfish that was about 3 feet long, and when he died they got a redtail catfish, had him for many years he was about 2 feet long and probably 20 lbs when he died. their tank was like a 175 gallon