Would it be fine to put a single Pea Puffer in with my Cray? MY Cray, Skeeter, is maybe 3 inches from head to tail. Maybe 5 inches with his claws extended. My Skeeter is my most valuable aquatic friend, the only, aquatic friend I have. He will get a 20 long with sand and plenty of hiding spots. I just don't want the puffer to bite ate him while molting and possibly killing him.