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FISH / new pets

Koi Fish Care & Pond Guide: TIps for Caring for Your Koi Fish


Knowing the ins and outs of koi fish care before bringing one home is important. These fish live long, fruitful lives and make great pets. Did you know, koi can learn to recognize their pet parents? Keep reading to learn more about how to care for your koi fish and their habitat the right way, along with what fish supplies you’ll need. 


How Experienced With Fish Do I Need to Be to Get a Koi Fish? 


These beautiful swimmers need a little more attention than some other species of fish. It is better if a pet parent has at least some experience with caring for fish prior to adopting koi into their life. They are best for intermediate fish parents. 


How Big Do Koi Fish Get? 


Koi fish can grow up to 36 inches long! That is 3 feet! These fish don’t always end up this size but can take up a lot of space depending on the type of koi fish you plan on getting. 


How Long Do Koi Fish Live? 


Koi fish are lifelong commitments. They can live for more than 50 years in some cases, meaning they will be with you for a very long time! 


How Should I Set Up A Koi Fish Habitat? 


In the wild, koi fish are used to living in water that doesn’t move too much. You want to recreate these living conditions the best you can to give them the best life. You shouldn’t worry, though, because it isn’t difficult to create the perfect koi fish care habitat. The best option is to set up a koi fish pond or aquarium


Koi Pond Setup: 


  • Koi grow quickly and get very large. Keep mature koi in an outdoor koi pond of at least 3 feet deep, with at least 240 gallons (908 liters) of water per fish.


  • Put the aquarium in a quiet area out of direct sunlight and drafts.


  • Cover the aquarium with a hood to reduce evaporation and splashing and to keep fish from leaping out.


  • To transfer new koi to the aquarium, float them in the water inside their bag for about 10 minutes so they can acclimate to the new water temperature.


  • If you're introducing koi to an existing school in an aquarium or pond, quarantine the new fish in a separate body of water for 2 to 4 weeks to be sure they are healthy.


  • On moving day, use a net to transfer the koi so bad water doesn't mingle with new water.


  • Whether they live indoors or outdoors, add no more than 3 new koi at a time.




  • Follow the manufacturer's instructions for choosing and setting up the right size filter for propper koi fish care.


  • An aquarium filter should be able to process all of the water in the tank 3 to 5 times an hour. For example, the filter in a 250 gallon pond would need to circulate at least 750 gallons per hour.


  • Add beneficial bacteria supplements to help break down waste in the habitat.


  • Test the water frequently. 


Heat and Light


  • Outdoor koi are hardy and will hibernate under ice in winter as long as their pond is deep enough to not freeze completely. (They won't survive in solid ice).


  • Your koi's pond should be partially shaded.


  • Indoor koi prefer water between 65 and 75 degrees Fahrenheit.


  • Install an aquarium light above an indoor aquarium to illuminate it for 8 to 12 hours a day.


What Temperature is Best for Koi Fish? 


Koi are pretty temperature-resistant— they can even hibernate under ice in winter. Just be sure your pond is at least three feet deep— otherwise, it could freeze solid, and koi aren’t that tough. When they live indoors, koi prefer cool water—between 65 and 75 degrees F (18 to 24 C).


What Do Koi Fish Eat? 


Koi fish are omnivores, meaning they eat both meat and vegetable components in their diet. In the wild, koi fish eat algae, plants, insects, worms and more. If you keep your koi in a pond outside, they should be given store bought koi fish food 4 times a day in 5 minute increments. If your fish lives in a colder climate, then how much and how often you feed your Koi may be different. Pet parents should always refer to the packaging to determin ehow much and at what times to feed their fish. This will make sure they are getting everything they need nutritionally. For indoor koi fish care, pet parents need to make sure they are giving them a balanced diet using koi specific fish food. 


Outdoor koi fish will naturally eat less during the winter months, kind of like a bear in hibernation. 


How Do I Keep a Koi Fish Healthy? 


You should contact a veterinarian regarding your koi fish’s care and  health. They are the ultimate authority and best source of information about how to care for your fish. Be sure to contact your vet if you notice any of the following symptoms, as they could be signs your pet fish isn’t feeling so good. 


  • Unusual swimming patterns.


  • Thinness of decreased appetite (in warmer weather). 


  • Abdominal swelling.


  • Inflamed or discoloured skin or fins.


  • Fins clamped to the side of their body.


  • Scrubbing body on rocks. 


Other Safety Tips: 


  • Fish and aquatic animals can transmit diseases to humans. Wash your hands with soap and water before and after interacting with your aquarium. Children, pregnant women, elderly people and people with immune-system problems should take extra care.


  • Keep fish away from food and areas where food is prepared.


  • Never release fish into the wild. They won't adapt well and can damage natural habitats.


  • Thoroughly wash your hands with warm, soapy water before and after contact with any pet or its habitat.


  • Adults should assist children with handwashing after contact with a pet, its habitat or aquarium water.


  • Do not use soaps or detergents to clean aquarium or décor, since they are toxic to fish.


Information in this article is not intended to diagnose, treat or cure your pet and is not a substitute for veterinary care provided by a licensed veterinarian. For any medical or health-related advice concerning the care and treatment of your pet, contact your veterinarian.