I have 5 pea puffers. They are alone in a 20 long. 2 guys, 3 gals. They spar and that’s about it. They have such great personalities. I also own Amazon puffers and spotted Congo Puffers. I a total nerm..... so I would like eventually like to have just puffers, frogs, turtles and cichlids. I have all of them already . My fish room always changes everyday. Since I do own 3 types of puffers, I’d say the peas are the easiest and not as shy as the others. I’m a sucka for a puffer ya