Is It Better to Have One or Two Goldfish? (Explained)

Goldfish are one of the most popular aquarium fish. You may have seen more than one goldfish in a tank. And you may have also seen a single goldfish all by itself in the tank. 

But, is it better to have one or two goldfish in a tank?

Well, this is what I’m going to answer in this article.

Goldfish are social fish so ideally, you should keep at least two goldfish together in a tank. Keeping multiple goldfish will provide companionship. And you can enjoy their interaction with each other in the aquarium. 

Now you know that you should keep at least two goldfish together, you may have questions about their size, gender, variety, etc. 

No worries, this is what we’re going to talk about in this article. 

Keep reading…

Goldfish image with test "Is It Better to Have One or Two Goldfish? (Explained)"

Why you should have two goldfish instead of one?

Goldfish image with test "Why you should have two goldfish instead of one?"

Goldfish are social fish. In the wild, goldfish school together with other goldfish. 

In your aquarium, you should try to emulate the natural habitat of goldfish to keep them happy. That’s why you should keep at least two goldfish together in your aquarium. 

Keeping a single goldfish could lead to depression and lethargy. 

Besides, when you have two goldfish, you can watch them interacting with each other. 

Generally, goldfish are very peaceful fish so keeping multiple goldfish together is easy

Also, if you keep male and female goldfish then you can breed them. 

What size tank do I need for two goldfish?

Goldfish image with test "What size tank do I need for two goldfish?"

One of the most important things you’ll need to keep in mind while keeping two or more goldfish in your fish tank is that you’ll need a larger tank to keep them

For two goldfish you’ll need at least a 60 gallon tank.

There are a few reasons why you need a larger fish tank to keep goldfish. 

  1. Goldfish can grow very fast and large

Goldfish can grow pretty fast. And they can grow pretty large. Goldfish can get as large as 14 inches (35 cm).

Besides, goldfish do not have stomachs so they can not store foods in their bodies. That’s why the food they eat is processed quickly and excreted out quickly in the fish tank. 

This waste breaks down in the fish tank and releases ammonia in the tank. Ammonia is harmful to the fish!

So if you keep goldfish in a smaller tank then the ammonia can build pretty quickly in the fish tank. 

On the other hand, if you keep goldfish in a larger tank then the ammonia will not build up as quickly as the ammonia will be diluted in a larger tank. 

  1. Maintaining constant water parameters

Goldfish need the water parameters in the ideal range constantly in the fish tank. 

If the water parameters in a goldfish tank are constantly changing then this stresses the fish which can lead to diseases. 

In a bigger tank, it is way easier to keep the water parameters constant. 

On the other hand, in a smaller tank, the water parameters can change pretty quickly. 

Can you keep two different varieties of goldfish in the same tank?

Goldfish image with test "Can you keep two different varieties of goldfish in the same tank?"

You can keep different varieties of goldfish together. But you have to keep a couple of things in mind while choosing the goldfish to in the same tank.

  1. Choose similar body shaped goldfish together

You should keep the varieties of goldfish together which have similar body shapes. 

Goldfish body shape can be categorized into two categories

  1. There are long-bodied goldfish varieties like common goldfish, comet goldfish, shubunkin goldfish.
  2. There are egg-shaped bodied goldfish like oranda goldfish, ryukin goldfish, ranchu goldfish, etc.

The long-bodied goldfish have streamlined bodies so they can cut through the water and swim fast. 

On the other hand, egg-shaped goldfish are bulky so they cannot swim fast.

This can become a problem during feeding time if you keep both types of goldfish together. 

As long-bodied goldfish can swim fast, they can easily consume all the food you put in the tank which can starve the egg-shaped goldfish

Besides, long-bodied goldfish are more aggressive during breeding time

So if you keep long-bodied goldfish and egg-shaped goldfish together then the long-bodied male goldfish will continuously chase and harass the egg-shaped female goldfish. 

And as egg-shaped goldfish swim as fast as long-bodied goldfish, the egg-shaped female will get stressed by the continued chasing which can lead to diseases. 

That’s why while choosing the goldfish to keep in your tank make sure to choose either all long-bodied goldfish or all egg-shaped goldfish. 

  1. Choose similar size goldfish together

The size of a goldfish affects its ability to swim faster. So while choosing goldfish to keep together in your tank, make sure to choose goldfish of similar sizes. 

If you keep small and large goldfish together then as bigger goldfish cannot swim as fast as smaller goldfish due to their bulky bodies, the smaller goldfish can eat all the food you put in the tank. 

Also, there is a possibility the smaller goldfish will harass the bigger goldfish!

If you keep a very small goldfish with a big goldfish then the big goldfish can eat the small one. 

This is not because goldfish are very aggressive. But because they’re always hungry and they will eat whatever fish fits into their mouth whether that is another small goldfish or any other species of fish. 

What should be the gender of the two goldfish?

Goldfish image with test "What should be the gender of the two goldfish?"

It is just a personal choice whether you should keep both male goldfish or both female goldfish or one male and one female goldfish. 

Obviously, if you keep a male and a female goldfish in your tank then at some point you’ll end up having babies in your tank. 

So if you don’t want any babies then you should keep either only females or only males together. 

Can you keep only male goldfish together? 

This is the question often asked and people are generally worried about the aggression among male goldfish. 

If you’re providing the ideal environment to the male goldfish in your tank then you’ll rarely see aggression among them. Sure, you’ll see males chasing each other sometimes. But it’ll be nothing to worry about. 

However, the males can get aggressive if you’re not maintaining the ideal water condition in your tank. Because poor water condition stresses the fish which causes aggression among them. 

Besides, if you’re not feeding sufficient food to the goldfish then they’ll compete for food in the tank which can lead to aggression among them. 

Can a single goldfish survive in a fish tank?

Goldfish image with test "Can a single goldfish survive in a fish tank?"

Ideally, you should keep at least two goldfish in your fish tank. This is because they’re social fish so they like to be in a group. And it’s interesting to watch them interacting with each other. 

That being said, if you do not have a larger tank that two goldfish need. Or if you just want to have one goldfish then you can certainly keep a single goldfish in your fish tank. 

If you keep the goldfish in at least a 40 gallon tank, maintained the ideal water parameters, and feed high-quality food then the goldfish will survive and live a long life in the fish tank. 

Conclusion 

Naturally, in the wild, goldfish live in groups. Besides, goldfish are very peaceful so it’s very easy to keep them together in a fish tank. That’s why ideally, you should keep at least two goldfish together. 

However, you can keep only a single goldfish in your tank. If you provide the fish with the ideal environment then the goldfish will live a healthy and long life on its own. 

I hope all the information I’ve given in this article regarding keeping two goldfish successfully in a tank will help you. 

If you have any questions or want to add anything on the topic, feel free to leave a comment below. 

Happy fishkeeping!

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Author
Prathmesh Gawai
He is the main author and editor at Aquagoodness.com. And he loves to share helpful information on aquarium and/or fishkeeping hobby. Prathmesh has over five years of aquarium and/or fishkeeping experience. Currently, he has a Betta fish tank. He has written hundreds of articles on various aquarium fish species and on fish tank maintenance over the last five years. Connect with him on YouTube here. Learn more about him here.

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