Goldfish are cheap and readily available in many pet stores which make them an attractive purchase for someone considering buying their first fish. Many people are mistaken to believe that these fish are very easy to care for, but this is not true. Another problem is that they are not compatible with most other types of fish as this fish is a cold water fish and there aren't that many tankmates that you can find for it.

It is common for pet stores to sell goldfish along with a bowl setup. In reality, this is a cruel thing to do. Bowls do not provide enough room for the fish to grow, become dirty very quickly, and the buildup of toxins from waste can produce chemicals which are harmful and even fatal to the fish. The amount of water one goldfish needs for healthy living is about 10 gallons.

If taken care of properly, a goldfish can live for many years, sometimes 30 or more. Depending on the type of goldfish, they can also grow up to a foot long. A lot of waste matter is produced by goldfish so having more than one in a ten gallon tank means more waste in the water which can lead to diseases and poisoning from an excessive buildup of ammonia and nitrates. Too many fish in one tank will also result in an insufficient supply of oxygen in the water. This will result in a shorter lifespan and stressed unhappy fish.

If you are still determined to buy a goldfish, setting up a tank is fairly easy. A tank with sufficient space should be purchased, holding at least 10 gallons of water per fish. Do not listen to the pet stores salespeople; they will tell you that one gallon per inch of fish is what you should use but this is not true for goldfish.

An air pump which blows bubbles into the water can be used, but is not necessary. Installing a filter is recommended. It will help clear waste and debris from the water which can produce toxins harmful to the fish. A filter will also help maintain the biological balance of the tank resulting in healthier fish. Substrate purchased from a store should be used, but do not use sand or rocks found in your own yard because you do not know what might be in them. A heater is not required because goldfish are coldwater fish. Decorations and plants will provide places for your fish to play and hide. Lighting should also be used so that you can enjoy the beauty of your fish and your tank, but is not absolutely necessary.