Goldfish (Carassium aruatus) are often the first type of fish that people will buy as pets. They are very easy to care for and are graceful to watch; especially the varieties with the longer fins and tails.
Originating in China where goldfish cultivation is still a very popular activity, the spectrum of novel goldfish types has expanded considerably as a result of intensive breeding programs. Over a hundred varieties provide the purchaser with a spectrum of choice ranging from the simple comet-type fish that you commonly find in the local pet store that might sell for a few dollars, to rare varieties that have elaborate coloring and fins that can cost many hundreds of dollars!
These fish can be very long-lived if fed and “housed” appropriately. Taking time to set up a top-notch aquarium is a bit of an investment up-front, but will help the fish potentially enjoy a full lifespan, which can easily top 10 years.
Aquariums
The goldfish is considered a very hardy species and is tolerant of temperature changes, but it still requires clean, chlorine-free water, proper water aeration and filtering, and enough space to move around. The little round goldfish bowls that often come packaged with a “goldfish-to-go” are not ideal aquariums. The typical round bowl is too small, especially for more than one fish, and does not provide easy setup of a filter or aerator system (a sale package would not typically include these latter component).
A 10-20 gallon tank is not excessive for one or two fish, and the typical rectangular aquarium tank package provides a top that will mount a filter and has entry points for an aerator system.
To ensure that the water is safe, make sure that it is dechlorinated using drops available from the pet supplier or allow water to sit for at least 24 hours (the latter is not considered as effective to clear chlorine). Take care to avoid temperature shock by checking the water temperature before you place the fish into the tank.
When cleaning the tank, avoid strong chemical cleaners and rinse everything very thoroughly since soap and bleach residues is toxic. The tank should be placed out of direct sunlight because this may lead to overheated water, and sunlight favors algae growth. If the tank is set up correctly, very little water turnover is needed.
Removing and replacing 1/3 of the water volume every 7-10 days will suffice. Full tank cleaning should be done on an as-needed basis, but in a good set-up, often full cleanings can be done at two or even three month intervals.

n Dr. Els Slurink practices veterinary medicine at Cleveland Pet Hospital and Health Center in Caldwell. She can be reached at 459-0709.