Environment
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

How Do I Choose the Best Goldfish Tank?

A.E. Freeman
A.E. Freeman

The best goldfish tank for you depends on how many fish you plan on keeping as pets. The more fish you own, the larger the aquarium you will need. Look at both the shape of the tank and the amount of water it can hold when picking it out. Although a goldfish kept in a bowl is a common image, you want to avoid choosing a small, bowl-shaped aquarium, as it is too small, even for a single fish. Bowls also do not allow you to put a filter in the water, which fish need to survive.

The average recommendation for the size of a goldfish tank is at least 10 gallons (38 liters) per fish. Some people recommend getting at least a 20-gallon (76-liter) goldfish tank for a single fish and adding 10 gallons (38 liters) for each additional fish. Still others suggest getting a 40-gallon (152-liter) tank even for a single fish. If you own three goldfish, your tank should be no smaller than 30 gallons (114 liters). While it's possible to get a tank that is too small, it's very difficult to get a goldfish tank that is too large.

The number of occupants will determine the best goldfish tank.
The number of occupants will determine the best goldfish tank.

Surface area of the goldfish tank is another important consideration. To find the surface area of the aquarium, multiply its length by its width. Each fish in an aquarium needs about 30 square inches (194 square cm). Determine if the tank is large enough for your fish by dividing the area in inches by 30 or the area in centimeters by 194. The more surface area a tank has, the more air is able to circulate and reach the fish in the water, which encourages growth and good health.

Goldfish tanks should be large and rectangular rather than small and bowl-shaped.
Goldfish tanks should be large and rectangular rather than small and bowl-shaped.

As a goldfish bowl is smaller at the top than in the middle, it is typically not large enough to allow your fish to thrive. Fish release ammonia, which needs to be filtered out of the water so that they do not suffocate. A fish tank also needs to be large enough to accommodate a filter.

The filter is a key part of the tank, because fish produce a lot of waste and bacteria. If the water isn't cleaned out, the fish will die or become very ill. Choose a tank with a built-in filter for ease or choose one that allows you to clip a filter to the side. Ideally, the filter will have replaceable pads.

Discussion Comments

anon990031

I had a 20g and I had four goldfish that we got from the fair but they lived for 3 years and then we put them in a pond for goldfish. The maintenance on the 20 gallon was unbelievable so If you do a smaller tank you have to keep up with the maintenance. I recommend a 30 gallon because goldfish grow and I did a canister filter on my 40g because I only have 1 arm but it has kept the water and levels in good ranges. Remember to test the water regularly.

Heavanet
I agree, Rundocuri. It is difficult to have a lot of goldfish in a small tank. I have two goldfish and some tiny neon fish in a 20 gallon tank, and they all do very well together. I wouldn't add any more goldfish though, because I would be afraid they may not have enough space.
Rundocuri

As a good rule of thumb, I think 10 gallons per fish is the best way to go when selecting a tank for your goldfish. If you plan to have more than four goldfish or just one or two goldfish and some other community fish, it's best to choose the largest tank possible. Goldfish thrive when they have plenty of space to swim, so like the article says, the larger the tank, the better.

Post your comments
Login:
Forgot password?
Register:
    • The number of occupants will determine the best goldfish tank.
      By: fivespots
      The number of occupants will determine the best goldfish tank.
    • Goldfish tanks should be large and rectangular rather than small and bowl-shaped.
      By: Sergii Figurnyi
      Goldfish tanks should be large and rectangular rather than small and bowl-shaped.
    • Each fish in an aquarium needs about 30 square inches.
      By: Arkady Chubykin
      Each fish in an aquarium needs about 30 square inches.