Breeding Koi Fish In 9 Steps

 Many people who get into raising koi fantasize about one day raising them for a living. They don’t know what all is involved in breeding koi fish though. I decided to let you know all about the facets involved in this business.

The Art Of Koi Breeding

Koi fish breeding is the act of breeding koi to get fry that you can raise to sell for profit when they get bigger. Breeding for koi fry is ideally done when the koi are three years old-or Sansai koi. Two year olds, or Nisai, koi are not as desirable because they have not developed enough yet.You can mate koi between the ages of three and six. This is the point where their reproductive systems are fully developed and they make prime mates. 

What’s cool is you can buy koi cheaply at a store like Petsmart and turn around and sell them after two years for at least $100 apiece. Nice return. If you set things up for optimum hatching you can have a lot of fish to sell. 

You can also raise purebred koi for a living which is trickier. I’m actually not covering this in this post.

This Is What You Need

There is a little bit of equipment you need to make a comfortable space for your koi. You need patience as the first ingredient though because it might take awhile for the koi carp to warm to each other. Other items you need are

  •  A 4-6 foot pond separate from the regular one. You can use a quarantine tank or show tank too.
  • Access to water
  • Aerator
  • Filter
  • Disinfector, like methylene blue
  • A cover, for privacy of course 🙂
  • A breeding mat you can buy or make your own

You got this. You’re good to go then. Let’s move on.

Who Is Koi Breeding For?

You are a koi fan or you wouldn’t be reading this article. I think you like the thought of taking your koi hobby from just a hobby to a full-time business. There are actually books on doing this that go into great detail on how to make this happen besides this simple article.

If you’re one of those people who think this would be a fun money-making hustle then being a koi breeder is right up your alley. Do you already have koi with desirable features you would like to see passed on to further generations? Then breeding koi carp is also a good business for you as many fry will likely be born. You don’t have to sell your favorites.

Your children can enjoy the koi too. Koi live long lives and some outlive humans. There was a koi that died back in 1977 named Hanako and experts believed was 226 years old! They usually have a lifespan of 25-35 years though. Still a long life.

Some things you want to do is ensure you keep your pond clean. Have a way of keeping predators out like a net or fencing so no eggs get grabbed.

This Is How Koi Breeders Get It Done

First thing, look for traits you like:

  Favorite colors of mine are kumonryu, or kikokuryu

  Do they have good body structure?

  Are they at least 3 years old?

1.  Set things up.

Feed your koi more frequently 4 times a day prior to breeding

2. Get a tank for your koi

  • Fill the tank and let the water sit for two days before putting the koi in it.
  • Put in live plants or some material such as nylon for the nest
  • Put a product called methylene blue in the water to disinfect the water and make a high hatchability rate almost guaranteed

3.Choose the koi you want at a ratio of 1 female for every 3 males

4. Get Your Koi Ready-

  • Put your koi in plastic tubs in the breeding tank to acclimatize them to the water.
  • After the 20 minutes, take your breeder koi out of the tubs and place them in the tank.

5. Ensure Your Water Is Clean and Oxygen rich-

  • Make sure you have good aeration going and proper filtration in the tank

6.Give these koi some privacy-

  • Cover the spawning tank with something to allow privacy and the koi males and females to get acquainted.
  • Keep the koi in the tank for at least 72 hours before checking up on them.

7. Check their progress-

  • In about three days check up on them if they’re mating.
  • If they are mating you will see the male koi carp vigorously pursuing the female
  • The female will be spawning her eggs on the nest and being chased by the males to fertilize her eggs with their milt-male fish semen
  • Leave them be for another 3 hours

8. Remove the adult koi fish-

  • Remove the breeder koi from the tank using a net
  • Take them back to their pond home.

9. Now we wait-

  • Wait 3-5 days for the eggs to hatch
  • Provide the eggs sufficient oxygen too
  • After ten days had gone since hatching you should see little fingerlings swimming around
  • And that’s how it’s done


 Where Koi Mate And Replicating the Environment

In the wild the koi carp choose shallow water as their preferred mating ground. If your pond has this shallow ledge then lucky you. You shouldn’t have a problem breeding your koi there. For those who don’t a show tank, or quarantine tank would work.

The advantage of having the shallow area in your own pond is also that your koi don’t have to be acclimatized to it and you can start breeding them then and there.

This Is How to Tell Male Koi From Female

Male koi have a more slender body than the female. At mating season males also have white growths on their heads and fins. The colors of male koi carp are more vibrant and their fins are pointed and opaque as compared to the females rounder, translucent ones.

In Closing

I hope that this article provides you the ins and outs of breeding your koi fish for a living. It is a very lucrative business as well as it is enjoyable. You can decide what you do with the koi fry. You can raise them as your own or to sell.

What are your favorite koi to breed? Let me know in a comment.

16 thoughts on “Breeding Koi Fish In 9 Steps”

  1. Wow 🤩this is highly informative! I sincerely do not know much about Koi fish, I only breed cat fish before but i think I’ve learnt a lot from this article to be able to breed my own koi fish especially the stage at which I can cross breed them. Thanks for sharing this article, it’s extremely helpful!

    • Hey there,

      I’m glad you were inspired by this post. You can click on any article on my blog to read even more to get informed. I never really tried cross-breeding. Were you planning on cross-breeding koi and catfish? – katfish or coifish. Thanks again for visiting my site.

  2. Koi fish is actually new to me and this is the first time that i am hearing about it. this is very detailed. I know that finding a good article does not come by so easily so i must commend your effort in creating such a beautiful website and writing an article to help others with useful information like this.

    • Hey Benny

      It’s never too late to start learning how to start breeding koi for a side-hustle. Maybe you could do well enough to make a living at it. Thanks for the compliment to my website. I want everything I write on here to be useful for the budding or seasoned pro koi enthusiast alike. Take care.

  3. Hello, Your step by step guide is very helpful for everyone. While reading I learn lots of new things regarding breeding Koi fish. As we know that Koi fish breeding is the act of breeding koi to get fry that you can raise to sell for profit when they get bigger. I hope everyone will enjoy your awesome guide on Koi Fish. Thanks for sharing such useful guide.

    • Hey Harish

      Good to hear that you thought my guide was helpful. The goal of mine is to write useful content about koi and koi keeping on my blog. Koi are living jewels and are attractive additions to your backyard pond. You can also add goldfish in to give your backyard pond feature more variety. Thanks for reading.

  4. Thanks for the nice post. It is really nice to read and the video was extremely wonderful. I love both of them. Thanks also for giving me a chance to discuss the topic. In this post you have posted nine steps to breed koi fish. Koi fish is the best fish for business. It has a lot of opportunities and features. The farmer needs to breed the fish. Your post can help them. It is a helpful post.

    • Hi

      Glad to meet you. I’m glad you liked my work. It is fun for me writing about this topic. You can have the best of both worlds by keeping koi and breeding them for profit. You don’t really need to breed them. It’s not everybody’s thing. If you want to do it though then this article on breeding koi fish would be extremely useful to you. Thanks for reading.

  5. Koi fish is fairly new to me and I must say your article has already made me fall in love with this fish already…and would love to train them throughout this covid-19 isolation period. thanks a lot for sharing i know it would be of great help to the public as it has been of help to me

    • I’m glad to have had a part in introducing you to koi. Some of them can be trained to eat out of your hand. Everyone’s feeling a little isolated and I think keeping koi could be a good thing to keep you occupied. I hope you are doing well during these trying times. Thanks for reading

  6. Thank you for this post about Breeding Koi Fish. It’s only now that I heard the name of this kind of fish, “Koi”. I enjoy watching this school of fish whenever I see them. I didn’t even expect that they grow in big sizes.

    I have a question and this is about the aerator which I see in the market, and in fishponds. What essential thing does it do for the fish?

    Second, what is the reason that on the ratio of male and female, the male is three times the number of females?

    • Hi Accad

      I appreciate you taking your time to visit my site. You could have been anywhere else and you chose to visit my website instead and for that I appreciate it.

      The aerator has the purpose of putting oxygen into the water . Fish need this oxygen in their water because that’s how they breathe.

      The number of males to female is just to maximize egg production. 

  7. Koi fish is one of my favorite fish as I once used to train them in my grandpa’s koi pond they are one of my favorite fish breeds after the catfish.

    I must say you have really done a great job on this awesome article as these tips are really good as they are more modern compared to the old ways we use to use….thanks a lot



    • Hey Juliet

      Are you doing alright? I’m happy to hear from a former koi trainer that she really enjoyed the read. You did a really awesome job on the comment. Thanks

  8. This is a really good one. I want to first commend the input of information into making this awesome koi pond with nice koi fish and finding time to write an article on breeding koi fish and the steps involved. the clarity in the steps you provided makes it easy to follow. i am happy. thank you

    • Hey buddy

      I am glad to hear from you. It is a privilege to be able to start this website and cover the topics related to koi fish and their care. The fact that you are very happy with my article and research makes me happy.


Leave a Comment