Right now I have a planted 3g Eclipse with a betta and an oto. Things are just fine now, but I enjoy watching the 5 cories I have in my 37, so I'm thinking of upgrading my 3g to something that could house the betta, oto and a pair of pandas (since they're neat to watch and they stay small). My research shows they can be kept in 5g tanks, but the number of fish is not specified. Any suggestions?