9 Fish That Can Live with Koi in A Pond

Are you thinking about putting more fish in your koi pond? Do you know which fish are alright for a koi to live with? Keep reading this article to find out the best pond-mates for your koi.

Koi are one of the most social pond fish species, when it comes to interacting with other fish, and even people. Depending on the pond environment, they can have a wide range of pond-mates including goldfish and even bass!

Fish That Can Live with Koi in A Pond

What Can Live with Koi in A Pond?

As generally friendly fish, koi will get along with anything that doesn’t prey on them. Of course, the first thing you have to consider when pairing fish is the habitat.

For example, tropical fish can’t survive in a colder outdoor pond, unless the weather is warm year-round or in a heated pond. Another good example is obviously saltwater versus freshwater fish because you clearly can’t mix those either.

Goldfish are usually the most popular choice to pair with koi because they’re the same genus. That being said, you can also pair koi with other fish commonly found in rivers, large ponds, and lakes.

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Here are the best pond fish to pair your koi with

  • Sunfish
  • Perch
  • Large Mouth, Small Mouth Bass
  • Other carp species, like grass carp
  • Catfish
  • Minnows

When adding fish to your pond, it’s probably not wise to just catch fish and add them to your pond. From the wild, they can carry diseases or parasites that they will very easily infect and ultimately kill your koi. It’s always best to stock your pond with healthy farmed or aquarium-bought fish.

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Do Koi Get Along with Other Fish?

Koi are almost always friendly with other fish. They tend to stick together for safety, but if your pond has a predatory fish, this won’t be the case. A koi can’t get along with something that sees them as prey.

Koi are not predatory fish, so they won’t try to eat anything in the pond, aside from tadpoles and insects. This is why the list of fish they can be paired with is so extensive.

If the other fish in your pond are also non-predatory, they will usually be a good fit, as long as there’s enough food to go around. Although, it’s not uncommon to see two fish competing for food.

Additionally, your koi may be seen defending itself from a more aggressive fish. This is done by bumping the other fish off course, since a koi doesn’t have teeth for fighting. In the case that the opponent is bigger, the koi will simply flee and hide.

Are Koi Aggressive Towards Other Fish

Because they don’t prey on other fish, Koi are seldom aggressive towards others. They may compete for food or defend themselves, but they will never attack another fish out of hostility.

As non-territorial fish, there are only two reasons that your koi will ever be aggressive, such as:

  • Fighting for food
  • Self Defense

In a pond with limited food sources or too many fish, a koi will compete with fish of smaller or similar size for food like bugs and tadpoles. Otherwise, they are usually harmless to other pond fish.

That being said, we’ve already stated that if there is an aggressive fish in your pond, a koi will defend itself against another fish of the same size.  After all, anything harmless can be turned aggressive, if necessary.

How Many Fish Can You Have in A Koi Pond?

The amount of fish you have in a pond always depends on the pond and the size of the fish. Either way, your pond’s whole ecosystem will be affected by how many fish and other aquatic life there is.

The general rule of thumb is for every inch of the fish’s length, you will need 10 gallons of water for it to have the right amount of room. An average koi is about 10 inches long. This means that in an average pond of a thousand gallons, you can have around 4 of these average-sized koi and keep them healthy and thriving.

Remember that if a koi has sufficient space, it will grow up to 3 feet long. So, if you only have a few fish in a much bigger pond, they’ll probably grow larger than the average size of 10 inches.

Another important note is that more fish will mean the water will need more aeration. If you have a large pond with quite a few fish, you will probably need multiple fountains, waterfalls, or other aeration tools.

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Can I Mix Goldfish with Koi?

As we’ve stated, goldfish make an excellent pond or tank mates with goldfish. They’re from the same hereditary line and eat the same things. Plus, koi and goldfish look similar, so they will school with each other.

Koi and goldfish are often found together in aquariums and ponds. Of all options, these two are the most compatible. This is because they’re distantly related, stemming from the same genus.

Here are some other reasons koi and goldfish are a common mix in ponds:

  • They’re both relatively low maintenance.
  • Both are passive fish.
  • They’re matching vibrant coloring.
  • Same water and ecosystem requirements
  • Same food sources

As a matter of fact, it’s common practice to feed koi goldfish flakes. Not only is this a cheaper option than normal koi pellets, which are made of the same ingredients. So, they already have all the nutrition your koi need.

Plus, if you have goldfish and koi, this means you won’t have to buy two types of food. Who doesn’t want convenience like that?

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Can Angelfish Live with Koi?

Not only can they not live with koi, but Angelfish can’t even live in the same habitat as koi fish. It’s not because Angelfish and Koi will fight, they just need completely separate environments.

Angelfish and koi fish are not compatible with each other. They have totally different habitat requirements, so they shouldn’t be sharing a pond or tank. To start, Angelfish really shouldn’t be in a pond at all, unless it’s been specially treated for tropical fish.

Here are the most important reasons why you shouldn’t be keeping koi with angelfish:

  • Different Water Requirements
  • Different Temperature Settings
  • Different Food Sources
  • Different Lighting Needs

Koi typically prefer colder water and will even swim to the depths to avoid the heat. Meanwhile, Angelfish, a tropical species, are found in warm water.

Further, all koi are freshwater species, and most domestic angelfish are found in saltwater. It’s basic fishkeeping knowledge to be aware that you can never put a freshwater fish in saltwater or vice versa.

As a side note, there are two types of angelfish: a saltwater and freshwater variant. But we already know that they aren’t meant for cooler water, so you’re aware that even a freshwater Angelfish wouldn’t work.

How Can I Make My Koi More Friendly?

Koi are typically friendly, but you can make extra sure all your fish get along by making sure there’s enough food to go around. Koi will also become more friendly with the person that they bond with.

You don’t really have to do anything to make your koi more friendly with one another. They’re passive fish that don’t fight, but if there isn’t enough food, they will compete for it. When there’s enough food, everyone’s happy.

Not only are koi friendly with other fish, but they’re also well-known to be social with people as well. They’re also said to be able to recognize their name and come even to the surface to be pet. If you regularly hand feed your koi, you’ll notice that they all appear at the top of the water, almost ready for the food.

You may even think that they knew you were coming. Actually, they do recognize the sounds and shapes of the one who regularly feeds them. Keep feeding your koi and spend some time with them, and they’ll see you as a friend as well!

What Are the Friendliest Koi?

There are more than one hundred different breeds of koi, all of which come from Japan and China. Of all these species, the mighty Chagoi koi are the largest, smartest, and the friendliest.

As we’ve said, a koi can grow to two or three feet in the wide-open spaces of a large pond. These Chagoi koi are usually the ones who popularly reach this length and are classified as the largest koi breed out of all of them.

They’re not just the largest either. Chagoi koi are also the most intelligent and the most social koi breed. When you hear stories of koi coming when called, these big guys are the ones they’re talking about.

It may be because they’re social, or it could be because they’re brave. Either way, these personable fish are a delight to have in a pond that allows their full growth and a life that promotes happiness.  After all, a happy fish will always be a friendlier fish!




Hello, I'm Jason. I'm the guy behind HelpUsFish.com. I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.

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