I have found my J.Ds to be reasonably peacful. I keep mine with ropefish, climbing perch and aurilis barbs. They rarely snap at the other fish, exept when they breed that is! Try having just a pair of the J.Ds with a shoal of bigger tetras, barbs or a few oddballs that could hold their own if the J.Ds breed. Bare n mind that all the new fish need to be at least 4" fully grown.