How Big Should An Aquarium Be For A Goldfish?
The goldfish ( Carassius auratus) is a species that suffers more than most. This is due to the unfortunate dissemination of misconceptions and little information about their care. Today, we’ll talk specifically about the ideal aquarium size for goldfish.
Goldfish are highly sociable creatures, with a strong personality, and often exhibit interesting behaviors.
How to estimate aquarium size for a goldfish?
It is common to hear that 100 liters of water is the minimum volume for a goldfish. In addition, varying amounts of liters of water must be added for each additional fish.
However, this volume is not enough for a single fish and the tank dimensions will be inadequate. The average size of a 100 liter tank is approximately 90 x 35 x 30 centimeters.
In fact, the ‘six times the length’ rule is appropriate for goldfish. This ratio provides an adequate volume of water.
It is important to note that the size to be taken into account is the maximum that adult fish can achieve. It is not the size of the young fish on the day it is purchased.
Differences between the common goldfish and the ballerina goldfish
Different sized aquariums are often recommended for common or single-tailed goldfish and ballerina goldfish.
The common goldfish has a single tail fin (tail) and an elongated body shape. It is the ‘traditional’ style of goldfish.
Ballerina goldfish are from a strain created to develop specific body shapes and usually have a double tail fin.
They are also distinguished by a variety of physical characteristics including head growth and large eyes. They are likely to have much more rounded and compact body shapes.
Adult goldfish size
A fully developed goldfish can easily reach a foot in length and a foot in width, including fins and tail. Adult fish can have a body the size of a grapefruit and weigh nearly a pound.
Varieties with shorter fins may have a shorter overall length, but will still have large, bulky bodies. With this information, we can already see that a 100 liter tank measuring 90 x 35 x 30 centimeters will barely allow an adult to turn around.
The common goldfish can reach larger sizes: at least 30 centimeters in length, mainly for the ‘versions’ with long fins, such as comets.
Why is aquarium size so important to goldfish?
Let’s take a look at some of the points to consider when setting the aquarium size for goldfish:
swimming skills
The double finned goldfish tend to have their swimming skills compromised. Due to genetic modifications he has undergone, he has long fins, rounded body, disproportionate head growth, poor vision – those bulging eyes! – and a compact body that doesn’t allow you to swim properly.
As they are not very agile, they need an aquarium with plenty of room to maneuver. Even if they are not fast swimmers, they still need a lot of space to swim. The common goldfish is more agile and faster.
surface area
The surface of the water is where gas exchange takes place. Thus, the greater the surface area, the more easily oxygen enters the water and carbon dioxide leaves.
This is important for goldfish, as they need a good level of oxygen in the water, and a larger area will be more beneficial.
Many goldfish have respiratory problems as their gills are not very developed. Therefore, it is very important that they have a well oxygenated tank.
Biological load
Generally speaking, the bigger the fish, the more waste will be produced. Waste excreted by fish is known as ‘biological load’. A fish with a high biological load will need a lot of water and big filters to dilute the waste.
Life expectancy
The common or single-tailed goldfish can easily live over 25 years. Double-tailed varieties, on the other hand, can live for 10 to 15 years.
Spending two decades in an environment that is too small, and in which there is nothing to interact with, will not be a pleasant experience.
For that reason, the pond should be big enough to provide environmental enrichment, things to do – decorations to play with, plants to swim and eat – and keep them interested for years to come.
What is the ideal aquarium size for goldfish?
A total of 120 x 50 x 50 centimeters should be the minimum for the double-tailed varieties, while for the common ones the tanks should be no smaller than 200 x 60 x 60 centimeters.
Ideally, common goldfish should be kept in large outdoor ponds, not aquariums.
This will give them a fair amount of water. They will have room to maneuver properly, room for decoration, can have mates, and exhibit a wide range of behaviors. That way they won’t be stressed, cramped or alone.
