What Do Koi Fish Eat?

Isn’t it amazing to see your swimming jewels rush at the pond’s edge with their mouths wide open begging for food? However, the last thing you want is to feed your koi something that isn’t good for them or that could be harmful.

In this article, we will look at healthy foods to feed your koi and on the tail end, those to avoid.

What Do Koi Fish Eat?

The fact that koi fish are polyphagous feeders and omnivores means that they can eat animal and plant matter. Koi will eat anything from algae and worms, to snails and insects. They can eat food that people love such as daphnia, tubifex, earthworms, duckweed, watermelon, and peas.

Other foods preferred by koi include rice, shrimp, lettuce, and cereal.

Shellfish, chicken, beef, fish meat, and the bread also make up the list.

Their food can be grouped into artificial and natural koi fish food.

Depending on the koi fish size will depend on how much they will eat.

Here is a more detailed look at the various foods that the koi fish eat:


Duckweed boasts high protein levels. They also contain a high concentration of methionine and essential amino acid lysine.

What is more, is that duckweed is rich in pigments and trace minerals that come in handy in the growth of healthy koi.


Shrimp contains Astaxanthin that is handy at enhancing the red coloration of your fish. It is not only excellent for koi but also other varieties of fish that you would desire to improve its red coloration.

Avoid giving your Shiro koi fish or black koi fish shrimp as they are unhealthy to them.


Watermelon is an excellent Vitamin C and A source. It is also rich in magnesium and potassium. All these supplies your fish with energy and fiber.


Mealworms are one of the best live foods for koi. They are rich with important nutrients. On top of that, obtaining them is effortless.

The fact that they are easy to raise means that you will always enjoy a fresh supply of them round the clock.

Their only drawback is that their exoskeletons are kind of harder to digest. Koi might not be interested in consuming them.

However, with time, they might learn how to consume them.


Crickets are readily available in many pet supply stores. This makes them a highly tempting choice for feeding koi.

They are available in an array of sizes.

Their costly nature is a put off too many koi owners. Moreover, you need to feed a great deal of them for your fish to benefit nutritionally.


Earthworms are effortless for koi to digest. They can be handy as a side role to assist recycle organic waste.

Worms are healthy and highly nutritious for koi.

Unlike some of the natural koi diets that we have featured on this primer, no considerable downsides exist with earthworms.

Rice and Pasta

Whole grain rice and pasta are a healthy and sumptuous treat for koi. These are welcome from conventional pellet food.

Pasta and rice are rich in carbohydrates, high body proteins, trace elements, minerals, and vitamins.

Instead of feeding koi raw rice and pasta, you should boil them first and do not put salt.

Once you have cooked the pasta or rice, you can rinse the starch off and refrigerate it for several days.

Adding some honey to your rice or pasta makes it more attractive to koi.

What Do Koi Fish Eat in The Wild?

In the wild, koi fish consume a buffet of animal matter, plant matter, bugs, and algae. It depends on what consumable morsels float their way.

What Do Koi Fish Eat Naturally?

Adding natural food to your koi’s regular dietary intake not only increases variety but also offers extra nutrition. While it is costly compared to pellet food, natural food provides more enrichment. Some of the natural foods that koi eat have been described above.

What Do Koi Fish Eat in A Pond?

In an artificial pond environment, koi meals are determined strictly by their owners. Some owners opt for an array of foods while others prefer to limit their choice of diet.

As koi live in minimal water volumes, you need to ensure that they are monitored and carefully filtered to guarantee prime water quality. The amount and type of food you serve your koi have a major impact on the water quality.

In a pond, the kind of food you give your koi must boast a balance of minerals and vitamins as well as other trace elements. This combination plays a big role in their long-term health.

One of the best foods for koi in a pond is brown bread. You can choose to add or not add honey.

In a pond, you can also feed them cockles and prawns.

Other meals you can serve them include:

  • Lettuce
  • Cheese
  • Oranges
  • Sweet corn
  • Worms

The rule of thumb when it comes to pond feeding is to give the foods sparingly. They need to be used as a supplement to a normal diet and not a replacement.

What Do Koi Fish Eat in An Aquarium?

There is no doubt that aquarium fish makes ornamental scenery inside the tank. You must keep your beauties happy and healthy?

What food can you give to ensure you achieve this goal?

Remember that giving koi in an aquarium the wrong food makes them weak. In more severe cases, they can die.

Giving them the correct food and at the appropriate time is paramount.

To keep your koi in an aquarium healthy, you can prepare meals in the form of tablets, pellets, or flake. Great fish food should contain trace elements, vitamins, and macronutrients in the appropriate amounts.

To guarantee optimum growth, development, and health of your koi, give them meals balanced with all necessary elements.

The Tetra Pond Koi Vibrance is a good choice for aquarium food for your koi. The Kaytee Koi Fish Food is an excellent alternative.

What Do Koi Fish Eat in The Winter?

As temperatures drop in the winter, koi have a difficult and stressful time acclimatizing. The ideal water temperature should be between 12 – 15 degrees.

The good thing is that they are always fine even in the freezing winter temperatures provided you take great care for them.

Because of the cold temperatures, kois spend most of their time at the bottom part of the water where temperatures are warmer.

In autumn, you should feed your koi wheat germ-based meals. This goes miles to ensure their metabolism gets used to the shift that will take place in the winter.

Always remember that fish digest food based on the water temperature that they are in. once water gets 10 degrees C, their digestive systems shut off and they will not digestive food.

Consequently, you should avoid giving them anything at these temperatures as undigested food in their bodies can end up being fatal.

If you notice that the koi are not hibernating from the top to bottom part of your pond, and they appear to be searching for food, avoid the urge to feed them. Even if you do feed them, as aforementioned, they will not digest their food.

When you notice that ice has started forming on the pond, avoid breaking it. Doing so sends waves through the water which can harm your fish. Instead of doing that, boil some water, put it in a pot, and hold it over the ice until you notice a hole melt.

Koi Food Categories (Ingredients)

One of the most important factors to consider when shopping for koi food is ingredients or category label.

Here are some of the common ingredients that constitute most of the koi fish food products:


Naturally, as aforementioned, koi are omnivores. In the wild, they will eat an array of plant and animal-based sources of protein for optimal health.

When in the market for the best koi food, you need to consider both the source of protein and percentage in terms of crude mass.

The prudent thing to do is settle for a protein that emanates from aquaculture like herring meal, anchovy, shrimp meal, or fish meal.

Certain brands utilize a range of various aquatic sources for the protein. Both the first and second ingredient on the label must be an animal protein source.

Animal protein is rich in important amino acids which carp the need for optimal growth.

The best possible diet is the one that features a protein content percentage of between 30% to 40%.

Plant Proteins

Adding plant proteins to feeds is more affordable than animal-based protein. Of great importance to note is that plant protein lacks essential amino acids which are important for fish as they are necessary for growth, organ, and tissue development.

Avoid brands that do not contain animal-based protein or with only several plant-based sources.

Immune Boosters, Minerals, and Vitamins

The best koi feed is the one that features a good mineral and vitamin profile. Such a diet promotes stronger color, growth, digestion, eyesight, skin, and healthy skin.

Ascorbic acid or vitamin are two of the most important vitamins.

These vitamins help koi combat viral and bacterial infections. They are also handy for the development of collagen and cartilage.

Immune system boosters are also important to the life of your koi. They can be synthetic or natural.

Synthetic and Natural Color Enhancers

Do you desire to improve the patterns and color of your koi fish? Color enhancers are handy in this regard.

Natural and synthetic ones exist. The latter is more potent and pocket friendly. The former is costlier and less potent.

Krill/shrimp oil and blue-green algae are the most common natural color enhancers.

Astaxanthin and Canthaxanthin are the most common synthetic enhancers.

Color enhancers are handy for fish keepers that desire maximum vibrancy and color. You can combine them with other ingredients to enjoy better results.

Fats and Oils

Fats are highly essentials when it comes to the health and life of your koi. They not only help carry energy but also soluble vitamins to your fish.

Nonetheless, you need to be careful not to overdo it as excess levels cause food to spoil faster. Additionally, they function as ”moisture” or catalyst for the development of, particularly molds.

Koi require fatty acids and linolenic. Fish oils like cod liver oil constitute fatty acids but linoleic acids are only 2.5%.

By contrast, vegetable oils boast low fatty acids but are high in linoleic acids.

A proper diet for koi ought to contain roughly 1% of both oil types.

Linseed oil is an incredible source for both fatty acids.

When is the Best Time to Feed Koi Fish?

Feeding koi is not as simple as feeding aquarium fish. Correct feeding time is important in making sure that they are not only healthy but also maintains a clean and safe pond.

When it comes to determining the ideal time to feed koi, plenty of things need to be considered. Primarily, you must know this fact about their biology – they lack a stomach. This means that outside factors influence their digestion.

Secondly, their cold-blooded nature means they cannot control their body temperature.

When it comes to how many times to feed your fish, you need to do it 3-4 times per day in the summer. In addition to that, you should do it in quantities that they will take in few minutes lest the pond will get polluted.

What Affects Koi Feeding Frequency and Amount

Some factors determine how often and much you feed your koi. Two of the most important ones are the size of the fish and the temperature.

Let us look at them:

Koi Fish Size

Smaller food portions are ideal for smaller koi. Some diets can be broken down into tiny bits for purposes of hand feeding.

Larger kois require more sustenance compared to the young or smaller counterparts.


Severe feeding or season changes like extreme low temperatures and high heat in the summer characterize some locations. Other climates are more temperate and might have regulated feedings throughout the year.

For more information regarding different climates and best feeding times, contact stores that are close to your current location.

Regardless of your climate, preparing your pond for spring needs annual maintenance.

Once winter sets in, it is prudent to note that koi hibernate. In the winter, the spend the entire season without food.

This means that in the summer, they need to not only eat but also store nutrition as much as they can. Failure to do so means that they will enter winter in very poor health and might result in sickness during spring.


As aforementioned, water temperature is highly important when it comes to feeding koi. It determines how often and what to feed your koi.

Check out this feeding chart for more information regarding feeding at various temperatures.

What is important to know, just like we highlighted previously in the article is that the digestive system of a koi depends on temperature.


Weather influences the amount of oxygen in your pond. Koi require oxygen for digestion.

The lesser the oxygen is in your pond, the more difficult or challenging it is for koi to digest food.

Some experts are against feeding koi right after or during a storm as during this time water tends to have low oxygen levels.

The ideal situation would be to feed your koi less food whenever oxygen is low.

Water Pump and Quality

More food to your koi fish means they poop more. During the feeding season, you need to monitor both the water temperature and quality.

Every water parameter needs to be kept within a healthy range.

When the level of oxygen drops in the water, koi are unable to digest to the best of their ability. If the pump fails to work then it means you will encounter a similar problem.

What to Avoid Feeding Koi Fish

Having looked at some of the meals you can feed your koi, let us now shed some light on those you need to avoid.

The golden rule is to keep off any low-quality koi food. These lack the delicate balance of minerals, nutrients, and vitamins that they need to not only grown strong but also healthy.

Refrain from serving any means that are high in carbohydrates such as corn and peas.

These foods are not only challenging to digest but also cause countless health issues if you eat them in excess.

Avoid these foods:

  • Frogs
  • White bread
  • Bugs you caught
  • Fish you caught

Final Words

While koi eat an array of foods offered to them, giving them poor-quality or inappropriate meals will only do more harm than good.

Such foods do not meet the nutritional requirements of your fish.

Therefore, it is prudent to invest in excellent-quality food to guarantee prime water quality, long-term health, and optimal development.

From our primer, we have shared everything you need to learn about koi feeding best practices.

By implementing all you have learned here, you will not only enjoy having healthy and color-rich koi but will also manage to provide a safe environment for their utmost growth.

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