Goldfish 10 Gallon Tank: 5 Information You Need To Know

Goldfish 10 gallon tank is often pictured swimming around in a tiny fishbowl in pet shops, which is where they can often be found. 

While this may seem like a good idea to the average person, aquarists who are experienced in aquarium hobby know that goldfish should not be kept in an aquarium that is so small for more than a few weeks. 

Have you thought about keeping goldfish in a 10-gallon tank? If you do then it is perhaps a question of how many goldfish you can keep in the tank? I have an answer for that.

Those species of goldfish that grow up to a maximum of 6 inches in lengths such as twisty tail and bubble eye could live in a tank as large as 10 gallons. 

The size of the aquarium is critical since if you want to keep larger goldfish such as an 8-inch fancy tail or even a 10-inch comet, you need a larger tank. 

Goldfish larger than 10 gallons will only grow to adult size if they are kept in a tank as a starter. If they are housed in a 10-gallon aquarium, they will have no room to grow.

Having learned just how limited the life span of a pair of young goldfish can be in a 10-gallon aquarium for a short period of time, the information in this article should give you the reasoning behind what you had just read. 

Goldfish with a 4-foot long body can be housed in a 10-gallon aquarium, but the average lifespan of goldfish in that tank is estimated to be around four years, which will be discussed below. 

It is important to discuss not only what happens when goldfish are kept too long in too small tanks and how one can increase the lifespan of goldfish when there is a small tank, but the consequences of keeping goldfish for too long in a too-small tank.

Let’s start by discussing how to keep goldfish in a 10-gallon tank if you’re ready to learn more about this!

What Species of Goldfish Can I Keep in a 10-Gallon Aquarium?

Tankmates for goldfish
Tankmates for goldfish

A 10-gallon tank is only large enough for keeping the smallest species of goldfish. 

Goldfish such as the twisty tail and the bubble eye goldfish can live in this size container. 

Both types of goldfish can grow up to a maximum length of 6 inches (typically between 3 and 5 inches) and both species can be kept in pairs so if you have no choice but to keep goldfish in pairs, the two species should make a good choice in a 10-gallon aquarium.

There is a recommendation to move the boys to a larger tank in order for them to be able to swim freely and explore the aquatic environment. 

In order to have a greater chance of winning, members of their own species should engage the goldfish. 

Don’t do what you may think you should do, and keep just one of these amazing creatures in a small 10-gallon tank. 

Goldfish that have no companionship can suffer due to their loneliness.

What Is The Life Expectancy Of Goldfish In A Small Tank?

If properly maintained, filtered aquariums are maintained properly, then goldfish can live for 10 – 15 years. Make sure the aquarium is spacious enough so that they can swim around freely and grow to maturity. 

Make sure the aquarium is equipped with the correct water parameters as well as a balanced diet.  It is common for goldfish to die sooner than expected when kept in too small of a tank due to elevated levels of nitrate that result from not properly cleaning the tank/cycling it.

Does A 10-Gallon Tank Have Enough Space For 4 Goldfish?

In a 10-gallon tank, it is possible to have between two and four small goldfish, however only having two is more advantageous. 

There is no reason why a pair of goldfish with twisty tails or bubble eyes cannot thrive in a 10-gallon aquarium if the water parameters are correctly handled. 

If you want your fish to grow up to full adult size, you should keep them in a larger aquarium for species like the fancy tail, butterfly, comet, or double-tailed goldfish.

You will need to upgrade your 10-gallon tank to a larger tank of at least twenty gallons if you intend to keep a few pairs of goldfish. 

There are, of course, a few species of goldfish larger than 6 inches in length. This is only true for the smaller species of goldfish. 

If you wish to keep the larger goldfish, such as the orlanda or the shubunkin, they can catch a maximum length of 12 to 14 inches, which means that they will require a 29-gallon (or bigger) aquarium.

2 goldfish are perfect in a 10-gallon tank
2 goldfish are perfect in a 10-gallon tank

What Happens If Goldfish Stop Growing?

According to the theory, goldfish only grow to the size of their enclosure although there are some facts that support the theory, it all depends more on the quality of the water than on the size of the tank. 

Goldfish are capable of growing until they reach their full maturity size when well-fed and kept in a large aquarium that is properly maintained. 

Depending on the species, they can reach a size of between three to twelve inches.

A growth-inhibiting hormone produced by goldfish accumulates in the aquarium’s water due to a buildup of the hormone. 

In the end, if tank water sits for a prolonged period of time, it is more likely to stop fish growth, keeping them smaller than usual. 

In actual fact, this can be problematic because fewer water changes equal a higher level of nitrate buildup in the tank, which can cause a fish to become infected and even die.

What Are The Best Ways To Keep A Goldfish Alive In A Small Tank?

You should keep in mind that if you are considering getting goldfish and you have no other option other than to get a small tank, there are a few things you must keep in mind for the fish to live as long and as healthy as possible. 

The following are some things you must keep in mind:

Put The Goldfish In Their Bowls And Remove The Enclosures

You can buy goldfish from a pet shop in a bowl, but immediately after purchasing the goldfish, you need to put it into a fish tank. 

The aquarium needs to have an air pump and a filter for the fish. It would be best if you put only two kinds of goldfish in your 10-gallon aquarium if that is all you can afford. 

You may choose the twisty tail goldfish or the bubble eye goldfish as the tiny goldfish.

Twisty tail goldfish aka Tosakin is a tiny goldfish
Twisty tail goldfish aka Tosakin is a tiny goldfish

Utilize Only Treated Water

Goldfish and other freshwater fish do not tolerate tap water for a number of reasons, including the fact that it contains chlorine which can kill goldfish in a matter of days! 

So, in order to ensure the health and growth of your fish, either filtered water or properly treated tap water should be used to fill your aquarium.

In a competitive market that is full of chlorine, Tetra Aquascape Water Plus Conditioner has developed a dechlorinating product that will help neutralize the harmful effects of chlorine.  

To purchase the product, simply visit your local pet store or order it online through Amazon.

Goldfish Should Be Fed Properly

You don’t want to overfeed your fish because that is one of the worst things you can do. 

When there is an excessive amount of food in an aquarium, it ends up rotting at the bottom, which increases the level of nitrites, thus actually contaminating the aquarium. 

A goldfish’s daily food requirements are not large (such as tropical fish flakes) as long as you do not waste your food.

Keep The Tank Clean Frequently

Unless they are regularly cleaned by having partial water changes every other day, aquariums can quickly become “dirty” and require regular maintenance to prevent this. 

If left on the substrate for long periods of time, rotting food and waste components turn into toxins which can be harmful to the fish if not removed.

Make Your Aquarium More Fun By Adding Decorations

You can create a happier, healthier aquatic environment by providing decorative items in the aquarium – these items will keep goldfish entertained and reduce stress. 

If you want to create an aquarium with reflections at the bottom, you can fill the bottom of the aquarium with colorful pebbles. 

Additionally, you should include a few caves or hiding places in the water where fish can hide or retreat or swim through.

Video About Goldfish 10 Gallon Tank


The larger species of goldfish such as comets or fancy tails, which are extremely large fish, require a bigger tank to keep them from stunting their growth rate and not allowing them to reach their full adult size.

Hence, it is concluded that a 10-gallon tank is suitable for two small species of goldfish, such as the twisty-tailed goldfish or the bubble-eyed goldfish. 

In general, it is advised to keep one inch of fish per gallon of water according to the general rule of thumb. 

In order to provide companionship to them and give them activity, you would like to keep them in pairs. 

In addition to that, you must also consider the combined length of the fish so that you can figure out what the total inches are.

The purpose of this article is to provide you with information that is useful to you. We appreciate you taking the time to read and wish you all the best with your freshwater tank.

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