[Adastra]

Whoever said it was ok to put a bunch of otos in a 5G with a betta should do a little more research. Otos typically need more space not only because of bioload concerns--although in a 5G tank would also be an issue. Otos are wild caught, and eat exclusively algae, and of that algae, they only eat a few specific kinds. Because they are wild caught, they do not usually eat prepared foods. If your tank cannot grow a reliable amount of algae to sustain these fish, you should not get them. Larger tanks with higher light have a higher growth potential for food for the otos, and more surfaces for algae to grow on.

I agree with most people in this thread, anything less than a ten gallon really isn't big enough for a betta and tankmates other than shrimp and snails.