I've kept paddlefish "dinks" they do not mind an aquarium with corners are quite good at maneuvering around. They will eat floating pellets but mine did quite well on feeder guppies as well. I would recommend a long wide tank, maybe 8' by 3' by 18" or so tall. I lost most of mine due to consistently moving around and they don't seem to like change very well. They are cool fish if you have the space to keep them, water temps are not a big deal but below 80 is better. Mine never grew beyond 10", watching them feed is fascinating...