Goldfish Care Basics

Common and fancy goldfish are Asian Carp, Carassius auratus. They Telescope Goldfish have been bred in the Orient for over a thousand years, and in Europe for over a hundred years to provide all of the colors and shapes available to hobbyists today.

Goldfish are a temperate fish found in cool streams, lakes, and ponds throughout Asia and part of eastern Europe, though all the Veil Tail Goldfish specimens found in the hobby today are captive bred. Goldfish can be easy to care for, however, they do require some care. Given proper care and a good, healthy environment, goldfish can sometimes live nearly 50 years!
Goldfish Equipment & Maintenance:

To keep a goldfish healthy, remember to provide them with plenty of clean, cool water.

Your goldfish's temperature should never rise above 74° Fahrenheit (about 23.5° Celsius), and ideally should remain between 65° and 68° F (18° and 20° C) so you will need a thermometer. Keeping a goldfish above 72° F (about 22.5° C) for Bubble Eye Goldfish long periods of time will result in Oxygen deprivation, which can cause nerve damage, heart damage, and can seriously hamper the immune system, making them more susceptible to many diseases, from easily treatable Ick to nearly untreatable swim bladder infections.

Keep your goldfish in a fish tank no smaller than a 10 gallon (about 38 liter), and make sure that a minimum of 6 gallons (23 liters) of the space in that fish tank is dedicated to each goldfish (each goldfish should have 6-8 gallons or more (roughly 23-30 liters or more) space in the goldfish aquarium). A 10 gallon fish tank is really only suitable for one goldfish.

This will provide sufficient space for your goldfish, so he can remain healthy, and this will allow the aquarium to help you keep healthy goldfish.

Goldfish should never be kept in a fish bowl.

Perform your weekly 10-15% water changes, so that your goldfish always has clean water and so that any waste that is not processed by the aquarium filter is removed.

Your goldfish will need a filter to keep the water from becoming toxic, and you will need to keep the filter in Ryukin Goldfish good condition. When selecting a filter, if you have fancy goldfish, make sure that the filter will not produce excessive current in your fish tank, and this will make it difficult for the fancy goldfish to swim.
Goldfish Food & Care:

Remember that your goldfish is an omnivorous (eats anything) scavenger, so provide him with a varied and high carbohydrate diet. Many goldfish foods are available on the market today, and most frozen fish foods are also appropriate, provided you do not feed meaty foods too often.

Goldfish have large appetites, but they also graze for food constantly. Don't let their 'mock hunger' and grousing around for food fool you into over feeding them. Your fish should be able to consume all the food you offer within two minutes of feeding. If there is food in the aquarium after this time has elapsed, this will contribute to poor water quality and make your goldfish more susceptible to disease.

You will only need to feed your goldfish once a day. If you feed more than once a day you will increase the waste your fish is producing and will also increase the risk of over feeding, so it becomes more important that you are performing your weekly 10-15% water changes and all necessary filter maintenance. Providing a proper diet will increase your goldfish's life expectancy and bolster their immune system.
Oranda Goldfish

Goldfish, like almost any fish, are aware that they are prey animals. In order to feel comfortable, they need to have lots of hiding places. Goldfish do not seem to be too particular about their cover, however, you do want to make sure that you do not use any sharp or rough decorations that your goldfish may get hurt on, especially if you are keeping any fancy goldfish that have impaired vision.

Like most other fish, they are more comfortable and will come out more and be more active if you can provide them with 50-75% cover - this means you should make half to three fourths of your tank space hiding places. Providing sufficient cover will reduce stress and therefore improve your goldfish's immune system, reducing chance of disease.
Goldfish Companionship:

Goldfish can, like most fish, be kept with fish with similar care requirements and temperament. However, this very quickly limits you Fantail Goldfish to other goldfish - fortunately, there are many different and interesting fancy goldfish to choose from.

When looking for a companion for your goldfish, remember to select goldfish with similar handicaps. If their disabilities are too different, it is very likely that some will out compete the others for food, and you can have a goldfish starve to death while another gets fat right before your eyes in your fish tank.
Finally:

Remember, goldfish are beautiful living creatures. It is the responsibility of the pet owner to care for their pet and provide a healthy environment. So give your goldfish space, clean, cool water, plenty of hiding places, and high-quality, high-carbohydrate foods and he should be a good companion for a long time.