Koi Fish Care – Tank Setup, Diet, Breeding and Habitat

In this post, we take a look at How To Do Koi Fish Care. Koi is one of the popular fish species in Japan. Koi is one of the hardy long living fish, they are recorded to live upto 50 or so years.

Koi are known to be one of the fish species known for used in the aquarium designs in popular hotels, gardens, mansions and the places that draws human crowd. They are considered lucky and also bring the good fortune as per some of the beliefs. They can turn an aquarium hobbyist into a caring fish breeder and also they can get a bit expensive to keep around as they grow.

NameKoi, Nishiki goi, Japanese Carp
Lifespan30 to up-to 70 years
Size25 to 40 inches
DietFlakes, pellets, frozen or freeze-dried foods
CompatibilityGold fish, Sunfish, Suckermouth Catfish, Bass
Tank SetupPond (or Larger Tank)
Care DifficultyMedium to Advanced Level
PH Level6 to 9

Types of Koi Fish

Koi fish comes into different variety based on changes in their color and markings. You can take a look at the below table to know some of their types.

Koi Fish NameColor and Marking
Butterfly KoiLong fins, elongated, skinnier bodies, red or yellow markings
Japanese KoiColorful, ornamental, white-orange mixture
Black and White Koideep black with white markings, unique color patterns
Gold Fish KoiAvailable in mixture of orange, silver and goldish pattern
KiFish with entire golden silver scales, orange markings

Depending on the type of the koi fish you would see, the marking and the color would vary. Females and males are easy to spot for some types. Female koi fish have larger fins, longer bodies and also rounded. Male on the other hand have the trailing fins.


You would find that Koi fish variety has the 3 feet or more. Some of the types may be shorter depending on the cross breeding and other breeders farm that has variety with specific size. Red, gold, black and orange are known color, some even have found deep blue markings too.

Koi Fish Diet

Koi fish are extremely active and so does their eating pattern reflects in the same way. Like goldfish they too have heavy appetite and need to be fed accordingly. Also keeping the algae and other vegetation in the pond also helps while keeping the koi fish in the tank.

You can also setup the automated fish feeder if you happen to miss their specific feeding pattern. They can be fed with insects, larvae, zooplankton, seeds and even some critters.

Here are some of the koi fish food that you can offer to the Koi.

Fish Food Name
Spirulina AlgaeIn pellet form, perfect for larger ponds, good for digestion
Processed Fish FoodFlake fish food, discs and processed food
Brine ShrimpCommon fish food for Koi
Worms/Germ FoodGood for diet, digestion and growth

In the wild koi fish eat variety of food available within the bio system available around them. Be it vegetation, insects, worms and other things in the available pond. In maintained ponds you would have to change the diet regularly and add different fish food items into the water.


Koi fish are suitable for the pond and the larger tanks. And so their filters are lot different than your average aquarium tanks. Which means you have to make use of the filters that can clear the large quantity of water and wastage. Filter should also take care of the bacteria so that there is no abnormal growth of algae.

Image Credit: Geekypixie

You can check out most common Koi Fish Pond Filter.

Here are some of the recommendations of the water filter for the Koi pond.

Filter Name
AlphaOneSuitable for always-on, less maintenance and easy to replace filtration
EvenFlow BIOMatAbsorbs variety of bio wastage, clears water and less maintenance
Magnet Bio BallsImproves water quality, increases oxygen levels and lower nitrate percentage
BioSteps Pond FilterSuitable for the 1000 gallon or more, Perfect in Garden Pond

Koi Fish Breeding

Koi being the most profitable fish for the farmers, they tend to invest a lot of money into breeding them. A lot of farmers breed koi on a professional level. Especially in Japan, a lot of koi fish are bred into farms and are exported around the world.

A dedicated breeding tanks or the ponds are made by the farmers. Koi fish of age 3 or older are chosen for the breeding. All the predators, tanks mates and the critters are removed from the pond. Breeding couples are kept separate. Fishes are fed 4 times a day. Fry mat is placed into the tank and then fry is separated from the tank and adults are kept aside. Baby koi are kept on pellet for few weeks. After growth they are isolated in another ponds.

Tank Mates for Koi Fish

Koi fish get along easily and without much conflict with variety of carp species and some other peaceful fish in the tank or larger pond. More space they have for movement, less conflict they have among themselves and others.

Here are some of the fish you can keep with the Koi fish.

Fish SpeciesBehavior
Gold FishSimilar in color, behavior, size and easy to keep, maintain and adjust with koi fish in the pond.
Grass CarpGood to keep with koi fish, especially for larger ponds.
Redear SunfishMost popular choice of fish to keep with the koi fish.
CatfishSuckermouth catfish especially good for tank cleaning also goes well with the koi fish. Only for larger ponds.
AmphibiansKeep frogs, salamanders and even newts into such large ponds.
OthersBarbs, Pleco, Golden Orfe and Tench.

A lot of small fishes don’t go along well with koi and can end up either getting killed or may not get enough food due to the overcrowded koi and other fish in the pond. Make sure to keep the compatible fish only into the tank. For example, fishes like guppies, danios, cichlids and fancy goldish don’t fit into the koi pond.

Apart from this, make sure to avoid fish that chase, over aggressive and those who dominate in the pond. It’d be harder to maintain the harmony into such ponds with koi. If possible stick to carp species of fish as they happen to go along with koi fish in the larger ponds just fine.

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