Judging by your tagline, only the paradise fish aren't warm water and I'm not sure about the axolotyls and mussels. You wouldn't have the axolotyl in the same tank as the fish, would you? So, I don't know if they're all in the same tanks or what. But all the fish would probably be happier with a temp more like 20, the paradise fish should be ok in that too though I don't know much about them and can't say about the axolotyl or mussel though.