buenos aires tetras

I currently have a 30 gallon tank with 5 BA tetras, I am ready to add more fish to it I’m not sure what to add, is there any other slightly bigger fish I could add other than tertras, I am also upgrading to a 55 gallon towards the end of the year so is there anything I could add as a juvenile...

I'm pretty new to the hobby. I just won two comet goldfish at the carnival without knowing what that meant. I've done a lot of research, and while one of the fish died a few days after getting them, the other appears to be fine. However, the remaining goldfish and a pleco are currently sharing a...