Long before my twenty gallon gets converted to saltwater, it will be a quarantine tank for my 50 G inhabitants. Once thats all done and out of the way, I want to disinfect the tank, and turn it either into a sanctuary for abused female bettas, or into a breeding house/community for Endler's Livebearers. I dunno what to do. What's your opinion?
Since the female bettas will fight if they are left alone with each other, like the males, you would need to make the tank all divided to have them live happily with one another. So just go with the endler's and it will eventually turn out to be a huge colony.
Tom