I really can't recommend any, because it's not a good idea. If you got rid of a couple, (not euhanize, but give/sell them) Or a separate place for your betta you could maybe get 1-2 ottos, but still thats pushing it.
ok i wont add anymore but one of my gouramis is really agressive (has gotten a darker color) and another is a really pale color (its always been and is not sick) can anyone explain