Originally Posted by kritas
Cories also have a minimum of 10G, and a Betta is absolutely mimimum at 5G, that is bare minimum. Like I said, maybe a shrimp or two, maybe a few mystery snails, thats pretty much all you have to work with.
Tyyrlym, hope you realise that pygmy cories are only abit smaller than tetras... I don't know, just personally thats not something I'd do. I like to give my fish a multitude of space to swim... You wouldn't be overstocking the tank with 3-4 Pygmy cories, but they are curious little fish, and love to swim around and play games with each other. You won't get their full personalities coming out in such a small tank...
Pygmy cories are *tiny* the 1 inch max size is something I wouldn't expect most of them to reach. A shoal of 6 wouldn't overstock the tank, but they are very shy, so I wouldn't be surprised if the betta picked on them and they spent all their time hiding. Also, being so tiny, they *really* need sand, or their barbs will quickly wear down, which will impair their ability to eat.
A dwarf frog, a shoal of otos, or a colony of shrimp would probably work better.