Do Goldfish Need A Big Tank?
Goldfish ( Carassius auratus ) are a species that suffers more than most. This is due to the unfortunate spread of misconceptions and little information about their care.
It turns out that goldfish are highly social and strong-willed creatures, and they often exhibit interesting behaviors. Today we will talk about what should be the ideal size for your fish tank.
How to estimate the size of the goldfish tank?
We commonly hear that 100 liters of water is the minimum volume for a goldfish. In addition, varying amounts of liters of water will be added for each additional fish.
However, this volume is not sufficient for a single fish and the dimensions of the tank will be inadequate. The average size of a 100 liter tank is approximately 90 x 35 x 30 centimeters.
Actually, the ‘six times the length’ rule is appropriate for goldfish. This ratio provides them with an adequate bath and an appropriate volume of water.
It is important to note that the size that must be taken into account is the maximum that the adult fish can reach. It’s not about the size of the young fish the day you buy it.
Difference between common or single-tailed goldfish and ballerina goldfish
Different tank sizes are often cited for common or single-tailed goldfish, and ballerina goldfish. The common goldfish has a single caudal fin (tail) and an elongated body shape; It is the ‘traditional’ style of goldfish.
Dancing goldfish are from a lineage bred to develop particular body shapes and generally have a double tail fin.
They are also distinguished by a variety of physical traits including head growth and oversized eyes. They are likely to have much more rounded and compact body shapes.
Size of the fish in its adult state
A fully grown fancy goldfish can easily reach 12 inches long and 12 inches wide, including its fins and tail. The adult fish will have a body the size of a grapefruit and a weight close to half a kilogram.
Varieties with shorter fins may be shorter overall length, but will still have large, bulky bodies. Considering this adult size, 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 12 inches in length, and often longer, especially for ‘versions’ with long fins like kites.
Why are tank dimensions so important?
Let’s take a look at some of the points to keep in mind when choosing a goldfish tank size:
Swimming skills
Ballerina goldfish tend to have compromised swimming skills. Due to the genetic modifications they have undergone, they have long fins, rounded bodies, disproportionate head growth, poor vision – those bulging eyes! – and a compact body shape that does not allow them to swim properly.
Not being very agile, they need a large turning circle with plenty of room to maneuver. Even though they are not fast swimmers, they need a lot of space to navigate; common goldfish are more agile and faster than ballerina fish.
Surface area
The surface of the water is where gas exchange takes place. Thus, the larger the surface area, the easier it is for oxygen to enter the water and for carbon dioxide to escape. This is important for goldfish as they need a good level of oxygen in the water and a large surface area will be better.
Many goldfish have respiratory problems, as their gills are not very developed. For this reason, it is very important that they have a well oxygenated tank.
Biological load
Generally speaking, the bigger the fish, the more waste it will produce. The waste excreted by the fish is known as ‘bioburden’. A fish with a high bioburden will need a large body of water and large filters to dilute the waste.
Life expectancy
The common or single-tailed goldfish can easily live for more than 25 years. On the other hand, elegant varieties should live for at least 10-15 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 this reason, the tank must be large enough to provide environmental enrichment, things to do – decoration to play with, plants to swim in and eat – and keep them interested for many years.
What size tank do goldfish need?
At least 120 x 50 x 50 centimeters should be the minimum for fancy varieties, while common ones should not be housed in less than 200 x 60 x 60 centimeters. Ideally, common goldfish should be kept in large outdoor ponds and not in aquariums.
This gives them a reasonable volume of water. They will have room to maneuver properly, room for decoration, they will be able to have companions and they will be able to exhibit a wider range of goldfish behaviors. That way they won’t be stressed, cramped or alone.
