Several online aquarium stores offer goldfish for sale, including PetSolutions and LiveAquaria.com. Both these stores offer a variety of goldfish, some of which are not available at standard pet stores. Specialty goldfish and koi are available for purchase from KoiToTheWorld.
Contrary to popular belief, goldfish do not do well in unaerated fish bowls. Instead, they should live in a fish tank of at least 10 gallons in capacity. Filtration and aeration systems are a must. Since they are a cold-water fish, they do not need a heater, but one may be necessary if warm-water species live in the same tank. Goldfish are able to live for decades, and some have been known to live up to 50 years.