A 25 absolutely isn't anough room for 5 goldfish, especially commons, comets or shubunkins. They require room both because they are in cool water instead of tropical temps (the cooler the water, the less you can stock a tank regardless of species) and also because they are very active fish. Goldfish (comets, commons and shubunkins especially) can easily reach a foot or more with proper care. If a 25 is way too small for some balas (an active cyprinid which grows to about a foot or so), why would it be suitable for common goldfish (another active cyprinid which grows to about a foot or so, in cooler water no less)?
I would venture to say, goldfish are the victims of more fishkeeping myths than any other species. They are insuitable for bowls and small aquaria -- most die in very short order. They do not grow to the size of their tanks -- they can simply be stunted by poor conditions......
IMO they are regularly victims of both ignorance and also their own hardiness.
__________________ Tanks everywhere, a well-stocked garden pond outside and a Horde of Flatcoated Retrievers  |