Goldfish Bowl

So you've finally done it.  You've bought that goldfish bowl.  Now, what do you do with it?

Keeping a goldfish bowl healthy is neither difficult nor time consuming.  However, there are some guidelines which you should follow.  These concern the general categories of filtration, bowl maintenance, feeding, and fish selection.


Many people do not realize that goldfish, like all other fish, require proper filtration in order to remain healthy.  Keeping them in a bowl without filtration requires a lot of maintenance and can be frustrating.  If the bowl does not have a filter, nitrogen based toxins build up which can severely harm or even kill your fish.   (See Aqua Notes - Nitrogen Cycle)

There are two types of filters which are most commonly used in goldfish bowls.   These are the sponge filter and the undergravel filter.  The main component of a sponge filter is the sponge.  While this makes for very efficient biological filtration, it also takes up quite a bit of space.  This makes sponge filters difficult to use in a bowl. 

The other option, the under gravel filter, is much better suited to a goldfish bowl.   The main part of this filter is a plastic plate which sits underneath the gravel at the bottom of the bowl.  An uplift tube completes the filter.  To set up the filter, rinse it with tap water and place it in the bottom of your bowl.  Then rinse the uplift tube and fit it into the opening in the filter plate.  Place a 1.5" layer of rinsed gravel on the filter plate.  Air tubing is used to connect a small air pump to the filter plate.  After the filter is set up and gravel is added, fill your bowl with conditioned tap water or with spring water.  The air movement causes water and fish waste to be drawn down into the gravel where bacteria feed on it.   This provides for the biological filtration necessary to keep your fish happy and healthy. 

Bowl Maintenance

Bowl maintenance needs to be carried out on a weekly and monthly basis.  Once each week you should remove half of the water from the bowl and replace it with either conditioned tap water, or with spring water.  In either case, let the replacement water sit for a half an hour or so, so it is the same temperature as the water in the bowl. 

The monthly maintenance will be slightly more time consuming.  Remove a fourth of the water from the bowl and put it in a clean container.  This container must have no soap residue.  Carefully net your fish and put them in the container with the water.   Then, stir the gravel and pour off the dirty water.  Fill the bowl three fourths with room temperature conditioned tap water or spring water.  Net the fish out of the holding container and return them to the bowl.  Then complete filling the bowl with the water you saved in the holding container. 


Goldfish are cold water fish which feed primarily on plants.  Goldfish food must have at least 12% protein.  If the diet contains too little protein, the fish will not grow properly.  The food should also have less than 5% fat. (See Aqua Notes - Feeding)

Vitamins and minerals are also necessary in your fishes' diet.  Perhaps the most important of these is vitamin A.  This is responsible for giving your fish their bright, healthy colors.

Fortunately for aquarists, providing a nutritious diet is not difficult.  There are several specially formulated goldfish foods on the market.  These are available in both flake and pellet forms.  However, these foods should be supplemented with other foods to round out your fishes' diet.  These can include blood worms, glass worms, tubifex worms, brine shrimp, Earthworm Flake, Spirulina Flake, Tropical Colors Plus, and Protein Plus.  A World Of Fish carries all of these foods, and a wide variety of others which your fish would greatly appreciate.

Feed your fish one or two times per day, but only as much as they will eat in about one minute.  It is important not to overfeed your fish.  Uneaten food decays in the bowl, leading to poor water conditions and an increased need for bowl maintenance.   Overfeeding is the leading cause of death in pet fish.  Feed your fish sparingly!

Also, choose two days each week during which you do not feed your fish.  Goldfish have been selectively bred to create highly unusual body shapes.  If they eat every day, they may develop impactions in their intestines, which can also lead to an untimely death.  The two days they go without food allows them to clear their intestinal tract, preventing the impactions.


And now the part you have been waiting for.  The fish.  How many, what types, and what size?

First, however, a very brief history of the goldfish.  The first records of goldfish being kept as pets come from the Sung Dynasty of China from the 900s.  From there they moved to Japan, Europe, and finally to the United States in the mid 1800s.   Goldfish have been kept as pets far longer than any other type of fish.

Goldfish are fairly dirty fish which can grow quite large.  Because of this, you must limit the number and size of the fish you keep in your bowl.  A maximum of one inch of fish per gallon of water can be kept in a bowl.  If you want to keep more that two or three fish, you will need a larger container such as an aquarium.  Many people even keep goldfish in ponds!  Larger containers allow you to maintain a more interesting selection of species and colors.

Goldfish come in a variety of colors and shapes.  Not all of them are suited for bowls.  Among the best bowl fish are the Fantails, Lionheads, and Moors.  The other types either grow larger, or are faster swimmers.  In either case, they do better in aquariums. 

When you get your new fish home, float the bag in your bowl for about 15 minutes.   Then open the bag and add about 1/2 cup of water from the bowl to the bag every 10 minutes.  When there is double the amount of water in the bag, wait another ten minutes, then release the fish.

Then, sit back, relax, and enjoy.

For further questions, please contact your A World Of Fish sales representative.