how to care for koi fish you need to know

how to care for koi fish

Koi Care Guide

Tips from home to health to food and fun



  • 10 things to know about your koi
  • How do I set up my koi’s aquarium?
  • What do koi fish eat?
  • How do I keep my koi healthy?

10 things to know about your koi

  • Experience Level: Intermediate
  • Size: Koi grow up to 36 inches (91 cm) long
  • Lifespan: They can live for more than 50 years and thrive in a wide range of water temperatures
  • Temperament: They are generally peaceful but may pick on slower fish
  • Origin: They’re a type of carp native to Japan
  • Did You Know: Koi can learn to recognize and take food from their pet parents
  • Koi fish originate from Japan and represent love and friendship in Japanese culture.
  • Most koi fish outlive their owners, having a lifespan of 200+ years.
  • They come in a variety of colors, not just orange. They may appear orange, yellow, white, red and black.
  • Owners who received their koi fish as a gift are believed to have good luck.
  • In Japan, koi fish are often passed down from generation to generation, as a family heirloom.

How do I set up my koi’s aquarium?

  • Koi grow quickly and get very large. Keep mature koi in an outdoor pond of at least 3 feet deep, with at least 50 gallons of water per fish.
  • Young koi can be kept indoors in an aquarium of at least 29 gallons.
  • 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 old 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 your koi habitat.
  • 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 20-gallon tank would need to push through at least 60 gallons of water each hour.
  • Add beneficial bacteria supplements to help break down waste in the habitat.
  • PetSmart offers free aquarium and pond water testing. Just bring in a sample of your water, and we can test the quality within minutes.

Shop aquarium filters Shop pond filters

Heat & 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 a light inside an indoor aquarium to illuminate it for 8 to 12 hours a day.

Water temperature

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).

Shop thermometers

How do I keep my koi healthy?

If your outdoor koi don’t seem to be eating in the winter, don’t worry; it’s normal for them to stop eating at temperatures below 40 F.

Be sure to contact a veterinarian if you notice any of these symptoms:

  • Unusual swimming pattern
  • Thinness or decreased appetite
  • Abdominal swelling
  • Inflamed or discolored skin or fins
  • Fins clamped to sides of body
  • Scraping body on rocks (flashing)


  • Fish and aquatic animals can transmit disease 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 hand washing 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.


how big do koi fish get

When the water is below 52 degrees, stop feeding your Koi. Most domestic Koi usually grow about 12 to 15 inches long. Japanese Koi usually grow 22 to 26 inches in long. Jumbo sized Koi grow up to 34 to 36 inches long.

You need to know 3 essentials koi fish care for the first time

koi fish care hand feeding koi fish Companion Animals

Koi Fish Care – 3 Essentials To Caring For Koi Successfully

Koi fish are one of the pedigree animals, just like dogs, cats and
pedigree horses.

They are highly inherited in order to achieve the relatively
magnificent range of different kinds of patterns and colours.

Since they are highly inherited, they are hereditarily weaker than
the plain ancestors- the similar is true for any of the pedigree animal.

Because they are hereditarily weaker, they are since more prone to
diseases and have weaker to the immune system than the common carp.

Here I would like to discuss about some of the essentials for making the Koi successfully.

Keeping a clean koi fish Koi Pond

The Koi fish pond should keep as clean at all of the time.

Keeping the Koi pond clean must be a work that you have to complete daily.

If you are not keeping the pond always clean, the Koi will live in a dirty environment and could probably die.

Don’t forget that the water is not only the place for living the Koi, but they eat, sleep and also use the bathroom as well.

Keep the pond as free of damaging contaminants should be a high priority if you are going to make a water garden.

You can begin with the water and it must be in form of crystal clear. If you can’t to see the bottom of the pond, it should be clean immediately if it is dirty.

Don’t forget that the Koi will eat anything in the home the pond so ensure that debris and trash is clean every day.

You have to spent the countless hours for building the pond,
selecting the plants, and landscaping the garden, so don’t damage
its attractiveness by permitting the pond clean, that the fish will experience.

The beautiful fish will experience not only with the issues of health
but also the colour will boring.

Treating the pond like a fish tank will assure that the pond keeps
clean and it is a location where everyone likes to see.

First you have to make a plan about how to clean the tank. You should have a system for filtration.

This will make sure that the water is with good quality by
repeatedly moving the water via a pump and gathering the debris in the filter.

The Koi try to eat more food in intention than in nature. So beware
of how much food that you are giving in each of the week, since
the more food the more waste that you will have to arrange within the pond.

Don’t forget that the waste is not at all from the fish, also from the uneaten food from the bottom of the water garden.

It is significant to blank the bottom of the pond, clean the pum system and drain.

This will make keep the water as clean and healthy for the Koi.

Correct Diet

For keeping the Koi fish happy and healthy, right diet is required.
There are number of special Koi foods in the market and all of
them are designed for one or number of the following: health,
colour, growth and boosting the system of immunity.

Having depleted considerable sums on the Koi, please do not
cooperate the health by feeding them as the diet of goldfish food,
trout pellets, bread or other titbits.

Koi wants proteins, vitamins, carbohydrates and trace the elements
in the diet like as the humans that do for health.

Koi foods are particularly formulated for providing the correct balance of the elements.

Since the Koi are Poikilothermic, they also want a change the diet
via the seasons, low proteins foods in winter and in low
temperature and high protein in the summer at high temperatures.

At less temperature, food possesses via the easy gut as slowly and is badly digested.

Food which keeps in the gut as too long and can begin to decay and
make the fish as very ill, and also weakly digested food refers more
waste and it means high Ammonia and means poor water quality.

In winter you should just nourish Koi fish once every day most
extreme and typically at temperatures lower than around 8 deg C
relying upon the span of your lake, you should quit bolstering inside and out.

However in midsummer, at high lake water temperatures you can encourage your Koi up to 8 times each day.

The brilliant decide is that any nourishment you give ought to be devoured in less than a moment.

On the off chance that there is still sustenance drifting around after
this time you are more likely than not encouraging excessively.

If all else fails decrease sustaining – recall more nourishment
implies more Ammonia and Nitrite – and to the extent we know
nobody has ever executed a Koi by starving, however it is
exceptionally easy to slaughter a Koi by overloading.

And in addition the amazing scope of polluted sustenance on offer,
you can and should offer treat nourishment, particularly in hotter
water conditions.

Nourishment, for example, lettuce, oranges, sweet corn and prawns
will all be eaten up with energy, once Koi figure out how to perceive the new sustenance.

At first you may discover Koi deny new sorts of sustenance –
however they will obtain new taste promptly particularly on the off
chance that they are utilized to a blended eating regimen.

You should never simply utilize the same pelleted slim down all the
time as Koi can get so used to only one eating routine they may
then reject every other kind of nourishment, including simply extraordinary formulae polluted sustenance. So shift the eating routine and keep them intrigued.

Protection From Predators

Because of their splendid shading and size, koi are sometimes difficult to spot.

Subsequently, they require security from normal predators, for
example, huge winged creatures and warm blooded creatures.
Mesh will keep most birdlife out.

On the off chance that raccoons,
bears, or other substantial predators debilitate, electric fencing
might be important to keep them out.

Managers of corporate lakes additionally find that they have to
shield their koi from good natured representatives who need to
encourage them, frequently with improper nourishments.

By Beginning the right set up, the Koi fish will flourish for years to come. Managing the Koi will be simplified and greatly improving the enjoyment.

How long can koi fish go without food?

Many experienced fishkeepers routinely leave their charges for two
to three days without making any provisions for feeding.

Almost any fish can go that long without fish food (more about that later, as well). However,

if you’re going away for longer, some preparation may be needed.

How often should you feed koi?

There are two main aspects to properly feeding your fish. These are feeding the right foods and feeding in the right amounts.

Each time you feed your fish, whether its three times a day or three
times a week, you need to make sure you feed only what they can eat in 5 minutes.

pond water

How do you treat green pond water?

Have only one inch of fish per ten gallons of water. …
Avoid direct sunlight as green water is due to small algae cell. …
Use pond bacteria to treat green pond water. …
Control amount of nitrates and phosphates as it is very harmful for
the pond’s ecosystem and helps in algae growth.

bacterial infections in pond fish

Fungal infections are recognisable on fish with their cotton wool-like formations.

In such cases a combined treatment advised: JBL Ektol bac Pond

Plus for the bacterial primary infection, complemented by JBL

AccliPond which rebuilds and protects the destroyed mucous membrane of the fish

what does koi keepers mean

A fish hobbiest who are into keeping and breeding koi fish

amount of food How much do koi fish eat?

Feed your fish up to four times per day. Only feed them as much as they can eat in about a five minute period.

Koi fish eat just about anything, from small bugs and insects, to
plants and algae at the bottom of the fish pond, to store-bought koi fish food. Koi will even eat people food.

gallons of water How do you calculate gallons of water in a pond?

Calculate Your Pond Water Volume
For Rectangular Pond: Water Volume = length (feet) X width X average depth X 7.43 gallons/cu. foot = GALLONS.
For an Oval Pond: Water Volume = 0.8 X ( length (feet) X width X average depth X 7.43 gallons/cu. foot) = GALLONS.
For larger ponds & lakes: volume is expressed as “ACRE-FOOT” of water.

natural habitats of koi fish

Where do koi fish live in the wild?

Koi or Common Carp. Common carp are large, greenish-brown freshwater fish native to Asia and eastern Europe. They are the first known domesticated fish, farmed for food over 2,000 years ago in ancient Rome.

fish waste

The pond owner should be concerned with both of these aspects.
While it is true that you can keep goldfish and koi in garden ponds
with no filtration, it severely limits the number of fish you can keep. … Goldfish and koi excrete waste into the water in the form of
ammonia, primarily through their gills.