Keeping Other Fish with Koi Carp

Difference between koi and goldfishTo determine which fish are able to share a pond with koi carp, it is first important to consider the characteristics of koi and their environmental requirements.
Koi carp are ideal for ponds that have a large capacity, plenty of cover and an efficient filter system. They require excellent water conditions and only thrive in large, deep ponds. They are very resilient and can withstand winter in a frozen pond, as long as you provide and maintain an air stone or floating heater to promote exchange of gases.

Koi are descendants of the common carp, and normally reach 36 inches and weigh as much as 35 pounds when fully grown. They were originally raised in rice paddies by Japanese farmers; with mutation, slight variations in color soon developed. Through selective breeding over the centuries, certain colors and patterns like Orenji, Doitsu and Midori developed.

So, given their size and habitat, what species of fish can safely share a pond with koi carp?




Golden Orfe (Ide)


Bottom feeder

-Orfe thrives well in ponds with efficient filter system and well oxygenated

-They are sociable fish and should be kept in schools of at least three

-Since they are surface dwellers, they are often the first fish in the pond to notice danger when it’s around.


Comet Goldfish



-Although they can live harmoniously in the same pond, they can interbreed and produce some ugly hybrids

- Goldfish can adapt readily to a wide range of pond conditions, are bright and colorful and breed easilyproducing a lot of baby fish

-Highly recommended species of goldfish for outdoor ponds are comet goldfish



Tench are peaceful bottom feeding fish 

Although it is a myth that tench will clean the bottom of your pond, they feed by picking food off the bottom and digging lightly, disturbing the silt and debris that settled at the bottom, thereby allowing the filter system to efficiently remove the waste. 


Can usually coexist

- Very hardy

- Effective at removing algae from the pond

- may latch on to slow-moving fish

-May die when temperature drops to 55° F

- Needs to be removed from the pond and placed in a tank or container during fall since it can’t withstand winter in the pond



Barbel fish keep close to the bottom and keep it very clean of food that’s been missed by the koi

They should have a good flow of water to keep them fit as they tend to get a deformed spine without a decent flow.



Sturgeon moves the bottom surface about more as it hugs the bottom

It’s irregular body movement disturbs the muck at the bottom of the pond and this gives the pump a chance to get it to filter


Can usually co-exist

-Koi and catfish can live in harmony for a while, but as the catfish grow they may damage or kill the koi.

-Contribute to the pond load

-Bottom feeder

- tend to kick up a lot of bottom debris, which can lead to cloudy, murky pond water

-Parasite and disease are another issue


Can usually co-exist

- Algae eaters

dojo loach and pond loach can thrive in cooler waters

About the Author:

My name’s Peter Hartono and I’m the founder and CEO of Just Aquatic- a proud Australian company that offers homegrown aquatic plants and aquarium supplies carrying top of the line brands including API, biOrb and Exo Terra. To find out more of our exciting offers and promotions check out our Facebook Page and follow us on Twitter at @justaquatic.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>