first we put 1 in a 29 gal w/ some other fish. 1 other gourami chased it and bit it. We separated them but it was too late. Ever since with the other ones they've been mostly alone in a 10gal. Our latest one, we had just put in some Afircan Dwarf Frogs, and then it got sick and died. The tank's conditions are all fine. About 3/4 of them were from 1 place and 1 was from another.