This is my setup:
10 Gallon
3 Dwarf Puffers
2 Oto's
2 Black Kuili loach
From what I read, you can keep 3 in a tank (1 dp per 3 gallon). You will however, have to make sure the tank is well planted to give them room to escape if one is agressive. The oto's seem to be fine, the Kuili loaches I...