So you want Koi Fish

So you want Koi Fish

By Factory Fish Tanks

So you want Koi Fish

For many years Koi fish have been a staple of Japanese culture with centuries of rich history with these magnificent fish. Starting from just carp, farmers began capturing and breeding the most colorful ones they could find. This led to a long history of rice farmers breeding these colorful carp to now being hundreds of thousands of dollars. The most expensive Koi sold for nearly 2 million and often breeders compete in competitions for these serious prizes.



Koi fish are often regarded as a symbol wealth and loyalty due to their gratefulness in the water and shiny coin like scales. These fish are not an easy fish to take care of either. With their high bioload from things like hand feeding and high fiber foods can easily clog filters. This means you need more space then you think you need for a Koi and this normally means going for a pond. Koi fish are often kept in pond but with the risk of birds, weather, and other animals often times tanks are best to keep them safe. Ponds are hands down the best way to keep a koi family since you can easily fill up to 10,000 gallons without going over 15k setup. When looking at Koi fish, they need a lot of room. Often you need about 250 gallon per fish, so just for two koi you're looking at 500 gallons!


Ponds are often better due to price, but when it comes to taking care of your beloved koi a tank keeps them much safer. From wildlife to hot weather the outsides may not be the best place for your $1000 japanese Koi fish. To keep their cold blooded animals safe you're looking for at least 3 feet in depth with some tarp you can cover the pond with. During winter times the pond may freeze fully if it is not deep enough. 




Often times you hear a myth that Koi fish grow to the size of their tank and do not jump but this is farther from the truth. A lot of store bought Koi do not exceed 12" so this is where the myth comes in when kept in a small tank. The fish grow based on their genetics and lineage and you should not expect a 3 footer from the pet store. Not only this but the other factor includes the health, food quality, temperature, overcrowding, & stress on the fish. Overall if you're looking for a healthy koi that you plan on keeping right then get it from a proper breeder and not a petstore. Trust us that extra hundred bucks will give you the peace of mind your fish won't pass away within a year.




Above is an 2400 Gallon Arowana tank so how big of an aquarium do you need for a Koi? Well the answer can vary on how big the fish is, but a good reference is around 500 gallons per fish. Before you run out, this is for a fully grown 24-30 inch Koi fish. A tank setup this size would run you between 8.5k and 14k for a full setup with sump, stand and everything else. A 500 gallon tank is no joke, from maintenance to running but to keep a Koi the right way this is the only way! To keep an average 12" Koi, you're looking closer to 250 gallons which is close to 4k and around 7k for a full setup.


1 comment

  • Yep I hate seeing those articles saying you can keep your koi in anything less than 400 gallons. These things need space, I plan on building a 5000 gallon pond 4 feet deep.

    Jonathan bevilaqua on

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