Ideal fish for small tank?
I started up a new 30 gallon freshwater several months ago, and purchased one of those cheap but pretty plastic 5 gals to use as my quarantine. The last of the fish in my 10 gallon salt tank died today (they were REALLY old) thus freeing up another tank to use as either quartantine or for fun.
I want to know what kind of fish I could put in either tank (as freshwater) that wouldn't be stressed by the small size. I was thinking about a goldfish, but it seems either tank is too small (is that true?). Betta is an obvious answer, but I was wondering what my other options were.