Goldfish 10 Gallon Tank: About Ideal Goldfish Tank Size

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!

How Many Goldfish In A 10 Gallon Tank?

Tankmates for goldfish
Tankmates for goldfish

In conclusion, a 10-gallon tank is suitable for one or two baby goldfish. Goldfish is considered an easy-to-raise fish. That is the reason why it’s so popular too. Every beginner who wants to start their aquarium can choose goldfish as their first choice. In cases you have no idea, goldfish can live for decades if you provide them with the right conditions. It’s longer than many fish out there.

Goldfish usually appear with a small bowl or small aquarium, but I must say, that is not enough for a goldfish if you want them to live happily. But if you raise the goldfish when they are still small fish, a 10-gallon tank is still a good choice to start. You should plan to move them to a larger tank as soon as they get bigger.

Here are some reasons why goldfish need a larger tank. The main reason, the goldfish lifespan is around 25-30 years. So think about how can you keep goldfish in a small tank for that time long. You can’t provide them a healthy life with a substandard tank even in 3 – 5 years, needless to say, 25 – 30 years. Goldfish just grow half of their real size if they are not in the right conditions.

What Goldfish Can Live In A 10 Gallon Tank?

Besides the baby goldfish we mentioned, what types of goldfish live in a 10-gallon tank? Have you ever wondered if the smallest goldfish need a small tank? Let’s see some information about Twisty Tailed Goldfish, which is the most popular small fish species below.

It is just large enough that it will not be cramped, but small enough that it is easy to maintain and keep clean.

Can twisty-tailed goldfish – the smallest fancy goldfish in a 10-gallon tank? 

Having the same size as the goldfish fry, twisty-tailed can be kept in a 10-gallon tank, but it’s the minimum tank size. The bright side is that it’s easy to keep the tank clean and also easy to control the tank’s conditions like temperature, and decorations… You should keep in mind that it is just large enough, it can be cramped anytime, although they are small goldfish.

Two twisty-tailed feel okay with living together in a 10-gallon tank (or bubble eyes too, if you like). But the compulsory condition here is you have to give them good care. Observing them to figure out what they need, and keeping an ideal environment… are what you can do.

How many comet goldfish are in a 10-gallon tank?

A healthy Comet goldfish can grow a maximum of 12 inches (or 30.48 cm). But when they are goldfish fry, they are just about 2 inches (or 5.08 cm) generally. Meanwhile, common goldfish size is from 4 inches (or 10.16 cm) to 14 inches (or 35.56 cm). So as you see, the Comet goldfish has quite similar in size to the average goldfish. But their specialties are slightly thinner and smaller inches of fish a little bit too.

Because of that tiny size, there are 1-2 fish you can keep in a 10-gallon tank. Comet goldfish is not the exception, you should change to a bigger tank as soon as goldfish grow up (about 2.5 inches). The next tank should be 20 gallons

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.

How Long Do Goldfish Live In A 10-Gallon Tank?

You know that single goldfish has lifespan is abut 25-30 years in the right conditions. So what if the 10-gallon-tank is already the ideal tank size for your goldfish, how long can they live? 

According to experts, 10-15 years is the number of times that goldfish can survive in 10-gallon tank. Obviously. it’s the maximum number and with the best temperature, the best food, the best care: water parameters, balanced diet… Another important point is that the tank is large enough for them to swim freely and comfortably. They can upsize if they can’t swim in a mature way in a small size tank.

What the experts say cannot be true in real life unless the goldfish receive all of the best living conditions. If a 10-gallon tank is small for them, they can pass away sooner than predicted. The main reason is that the tank was not properly cleaned, and nitrite levels spiked.

How Big Do Goldfish Get In A 10-Gallon Tank?

There is some truth to this, but it is not as simple as it seems, and it has more to do with the quality of the water than the size of the tank.

Goldfish continue to grow as long as they are given the right care. In reality, the majority of fish are what are known as indeterminate growers. So, unlike humans, they continue to grow until they pass away. Poor water quality and careless handling are the main factors that inhibit a fish’s growth. 10 gallons of water quality in tiny aquariums or bowls is frequently very bad. 

Reduced filtration and irregular water changes can limit the size of goldfish. Stunting is the result, and that is not good. Instead, it is a symptom of poor health, and often, stunted fish develop deformities and pass away at a young age. But as I mentioned before, the maximum size can be approached if the has enough space to live.

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.

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 comet 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 it and wish you all the best with your freshwater tank.


Can a goldfish live in a 10-gallon tank?

Maybe yes. 10-gallon tanks are a reasonable size for their value. They are very inexpensive tanks that are simple to transport and set up in a bedroom or small apartment. They make the perfect “desktop tank,” but a 10-gallon tank is rather little in comparison. You can only do so much with it, and if you’re just starting off, they’re even more restrictive because they’re not as forgiving of mistakes.

Do goldfish get lonely?

It is advised to have at least two goldfish in an aquarium to foster interaction and camaraderie. Lethargy and depression are common in solitary fish. Most communal fish can be kept with goldfish because they are typically not hostile, as long as the other fish are larger than the goldfish’s mouth. You should be careful if you want to put a betta fish for cohabiting with goldfish.

In a 10 gallon fish tank, what types of goldfish can you keep?

– Bubble Eyes Goldfish.
– Celestial Eye Goldfish.
– Pearlscale Goldfish.
– Pompom Goldfish.
– Butterfly Tail Goldfish.

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