What do koi fish eat? Feeding koi pellet food

What do Koi Fish Eat? Best Koi Food Options

Koi fish brighten up outdoor spaces and bring elegance and excitement to any backyard pond they inhabit. In order to keep your Koi happy, it is important to provide the proper food so they can thrive. In order to do so, you’ll need to ask yourself questions like – what do Koi Fish eat? What are safe Koi foods? What is the best fish food for Koi?

One of the best parts about owning Koi fish is that you can quickly teach them to eat right out of your hand. Feeding times are fun and interactive with Koi. This guide will cover everything you need to know about feeding this beautiful species of fish such as the best ingredients for Koi, foods to avoid, and feeding frequency.

What do koi fish eat in the wild?

Koi fish are omnivorous fish, meaning they will eat anything from plants to algae to small shrimp and insects. As descendants of the common carp, Koi like to eat algae, insects, worms, seeds, crustaceans, and plants. They need a good variety of nutrients in order to stay healthy which holds true whether they’re in the wild or captivity.

What do koi fish eat in captivity?

When trying to keep Koi fish healthy, it is a good idea to try to mimic their natural diets. This translates into a lot of variety, including treats from the kitchen and store-bought Koi food.

Koi Food

The easiest way to ensure a balanced diet for your Koi is to make sure a majority of their diet is store-bought Koi food that is specifically designed for Koi. Koi food comes in three primary shapes – flakes, pellets, and bars. There are also two primary dispersal methods – floating and sinking. The size and age of your Koi will help guide the selection process. Here are our recommended koi foods:

Leafy greens and vegetables

Lettuce is a delicious treat for Koi. They love to snack on it so if you have leftovers, they will happily eat the lettuce before it goes to waste. 

However, lettuce is not typically high in nutritional value (mainly water weight and fiber) so be sure not to feed too much of it to your Koi as they need room for other valuable nutrients. Spinach is also a good treat for your Koi and has more nutritional value than lettuce.

Never serve leafy greens with salad dressing or spices as the additional ingredients could be toxic.

Citrus and grapefruit

Koi are fond of grapefruit and will also consume orange and lemon slices. To feed these treats, simply cut the fruit into small sections, remove the rind, and let them float at the top of the pond. 

The Koi will eat all of the fruit except the skin/rind, so it is often easier to remove this initially versus having to fish it out later, Additionally, the skin or rind can clog the koi pond filter which will create more work for you. 

Cheerios

Koi love Cheerios! They are a low residue and low nitrogen treat. They’re a much better option than other high-sugar breakfast cereals. However, Cheerios contain a significant amount of carbs so they should be fed in moderation as high-carb foods can be difficult for koi to digest when given in large quantities.

Garlic 

Garlic is another great snack for Koi. While it is toxic for most household animals, Koi love it! It is a healthy treat that helps boost their immune systems. To serve it to your Koi, chop up pieces of raw garlic or soak the pellets in garlic and sprinkle them in the pond.

What should you feed your koi fish?

Feeding your Koi a balanced diet is important. As a koi owner, you need to know what is safe to feed your fish. The easiest way to accomplish that is to make sure a majority of their diet is store-bought Koi food that is specifically designed for Koi. 

Koi food comes in three primary shapes – flakes, pellets, and bars. Flakes are recommended for Koi fry (baby Koi) and young Koi. Koi pellets come in a variety of sizes and need to be small enough for your Koi to swallow whole. Bars work best for the largest Koi, although they can still provide nutritional value for smaller Koi fish, who will nibble on the bars.

Feeding koi fish

There are two primary dispersal methods for Koi food – floating and sinking. Most Koi prefer floating foods and it ups the entertainment value of feeding, as you can watch your Koi swoop up to the surface to hungrily grab their food. Sinking foods are also an option but it is much harder to monitor food intake, as you won’t be able to physically see how much food is being consumed. If you consistently overfeed, you can spike the water parameters in a harmful way.

The best ingredients for koi fish food

It is important to buy high-quality Koi food. If you skimp on quality, you will likely feed your fish a product with a lot of fillers in it, instead of high-quality ingredients that support their health. Check out the ingredient list to better understand what is in your Koi food. The first ingredient should be a protein, typically fish-based, and the second ingredient should be a carbohydrate. Here are good ingredients when considering a potential food:

Primary Ingredient 

  • Fish Meal
  • Squid Meal
  • Shrimp Meal
  • Anchovy Meal
  • Blood Meal
  • Herring Meal
  • White Fish

Secondary Ingredient

  • Wheat Germ
  • Soybean Meal
  • Corn Gluten

Nutritional content breakdowns are important when considering a food. You want protein to account for about 32-36% of the nutritional content and fat to account for about 3-9% of the food.

Factors that Affect Koi Feeding

There are a number of factors that affect how and what you should feed your Koi. Koi are constantly growing and their digestive requirements change with the water and weather conditions so you don’t feed them the same way in the summer and winter. This is a nuance to feeding pond fish.

1. Koi Size

The size of your Koi affects their ability to consume food. Smaller fish need smaller food pellets. For example, fish that are three inches or smaller will do best with tiny pellets that are about 1/8” in diameter or smaller. 

Larger fish tend to eat larger pieces of food. For example, fish that are four inches or longer can consume pellets that are 3/16” in diameter.

This is Koi size feeding guide is a helpful resource that we recommend saving.

2. Seasons

The carbohydrates and proteins levels that your Koi need in their food varies with the temperature. 

Koi tend to be more active in cold water than in warm water due to the change in oxygen content, which means they will be hungrier during the winter months. Higher levels of carbohydrates will fuel their activity levels. However, stop feeding your Koi if the temperatures drop below 40 degrees Fahrenheit as they will likely hibernate. You will just be adding food to the pond that will not be eaten, which is bad for water quality. You can also think about adding a koi pond heater to stabilize the temperatures during this time.

In the spring, both before and after mating season, plan to feed a high-protein diet. 

In the summer, when the water is warmer, Koi will slow down. They will need to consume higher levels of protein to maintain their form. For the warm months,  switch to higher protein food.

In the fall, especially when temperatures begin to drop, Koi will prefer carbohydrate-rich food in order to prepare for winter.

3. Temperature

The seasons are helpful guides for balancing carbohydrates and protein in your Koi’s food. To be more precise, you can also measure the temperature of your pond water to determine the optimal food.

Below 40 degrees Fahrenheit, stop feeding your Koi. Your fish will go into hibernation mode. You will waste the food if you feed at really cold temperatures.

Carbohydrate-rich diets are best when the water temperature is between 40-50 degrees Fahrenheit.

Protein-rich diets are better in warm water situations. If the water is about 70 degrees Fahrenheit, choose a protein-rich diet. 

At all of the intermediate temperatures (50-70 degrees Fahrenheit), it is recommended to provide a mix of carbohydrates and proteins.

4. Weather and Oxygen Content

Oxygen impacts how your Koi will digest food and what type of food is most appropriate. Because of this, weather can impact the oxygen saturation of your pond’s water and subsequently, how you should be feeding your fish.

When it is stormy, the oxygen content of the ambient air drops. Unless your pond is very deep, that drop will also decrease the oxygen content of the water.

With less oxygen available, your Koi will be less active so you’ll want to feed them less than normal and focus on protein-rich foods.

Extremely sunny and hot weather can also reduce the oxygen saturation of the pond by heating up your water (and causing it to evaporate). Similar to the storm situation, warm water has less oxygen, so your Koi will appreciate a protein-focused food.

5. Water Quality and Water Pumps

Oxygen is important for Koi feeding and food digestion so it is an important factor to consider. Water quality is an important element for maintaining sufficient oxygen content. 

For example, algae will produce oxygen when they’re growing, which can be helpful. However, once algae dies and sinks to the bottom, it stops producing oxygen. Further complicating this issue is the microbes that will feed on the dead algae. Microbes love oxygen and will pull large amounts out of the water, putting your Koi in a difficult low-oxygen situation. Plus, they’re fueled by the dead algae, further increasing their numbers (and subsequently, their oxygen removal capabilities).

Pumps can help potentially remedy the oxygen situation. Turning on the Koi pond pumps and filters will prevent algae from growing by circulating the water and aerating the pond’s water.  Most pond canister filters will help with this too. With more oxygen available, your Koi will be more active so a carbohydrate-rich food will be more appropriate.

Installing a waterfall can also help re-oxygenate your pond. Don’t feed your Koi if your pump or waterfall breaks, as the oxygen levels will be too low. Instead, focus your energy on fixing the pump as quickly as possible. 

How Does Food Affect Koi Fish Color?

Various elements in Koi food can affect the pigments in the scales of your fish, which in turn will impact their color. Similar to the story told to young children about turning orange after eating too many carrots (which contain carotenoids), the food that we consume has an impact on our appearance.

In general, carotenoids can impact the orange, yellow, and red colors of your fish Some people have given their fish such concentrated carotenoid doses that their fish have had white spots turn pink!

Spirulina will also enhance the color of your Koi. This nutritional supplement enhances the color red because it contains a high level of carotenoids. Spirulina is also rich in protein and good for your Koi’s immune system.

However, don’t expect new food to change the color of your fish immediately. Managing the color of your koi through food requires multiple feeding over a period of a few weeks.

How often should Koi fish eat?

The biggest mistake that koi fish owners make is overfeeding their fish. When feeding, owners should sprinkle the food slowly for a maximum period of five minutes. In an ideal feeding, the koi will not leave any food behind, as leftover food will decay and make the water quality in the pond worse. You can feed your koi up to three times a day, or less in cold weather. Do not feed when temperatures are below 40 degrees Fahrenheit. Lastly, feed away from the pond skimmer and pump to avoid clogging issues.

Feeding koi in a koi pond

Store-Bought Koi Fish Treats

When purchasing store-bought koi treats, prioritize healthy, nutrient-packed foods for your fish. Examples of healthy fish treats include:

  • Bloodworms
  • Earthworms
  • Black Mosquito Larvae
  • Shrimp
  • Clams 

Foods to Avoid Feeding to Koi Fish 

Lastly, it is important to know what foods to avoid feeding to your koi. 

Foods that are very high in carbohydrates should be avoided as they are hard for koi to digest. These foods include peas, corn, and bread (especially white bread). 

Also avoid feeding your koi anything you have caught yourself, such as fish or bugs. Wild-caught fish and bugs could introduce parasites or other sicknesses to your fish and leave you with a new problem to solve. 

What is the Best Koi Fish Food?

Since there are many elements involved in Koi feedings, such as season, temperature, size of fish, and oxygen concentration, there are a huge variety of Koi foods available on the market. However, many Koi foods don’t have the right balance of carbohydrates, proteins, and nutrients. The “best” koi food really depends on the various factors listed above. Below, we’ll explore eight excellent koi food options for different situations:

8 Best Koi Fish Food options:

Best for Growth: Hikari Saki Growth Pellets

Hikari Saki Growth Pellets is recommended as the best growth-focused koi food on the market. This product is marketed as “A Daily Diet For Show Koi Offering Accelerated Growth.” The primary consideration during the development of this diet was the natural, omnivorous requirements of Koi. While a high growth formula, this food is not associated with increasing the chances of internal fat deposits which are a known problem for koi.

Features:

  • Minimum 40% protein and 9% fat content
  • Available in different sizes
  • Floating pellets
  • Respected Japanese brand

Pros: 

  • Helps Koi fish grow at a fast rate
  • High quality food that helps support cleaner pond water
  • Koi love it

Cons: 

  • Expensive
  • Some users did not report color improvements

Best Premium Choice: Dainichi Koi Food

This premium food from Dainichi is designed for larger Koi (8 inches in length or greater). It has a large pellet size. 

Additionally, it has a high protein content of 42%. The high protein content means this food is recommended for summer, although it could easily be used into the spring and fall as well, when temperatures are warmer.

Features: 

  • High protein content – contains 42% minimum protein content
  • 4% minimum fat content
  • Contains calcium montmorillonite clay (same clay found in the ponds where Koi are native). Helps keep the pond cleaner while feeding this food.

Pros:

  • Contains Spirulina, a known color enhancer for koi
  • Includes unspecified vitamin mix, important for immune health
  • Considered one of best koi foods on market

Cons: 

  • Expensive

Best Budget-Friendly Option: Kaytee Koi Food

This is an excellent budget-friendly koi food that provides a good balance between protein, carbohydrates and fat. Because of its relatively high protein content (35%), it’s ideal for spring and fall.

The main sources of carbohydrates are soybean meal, wheat flour, corn gluten, and wheat germ meal. These carbohydrate sources are less expensive, which is how the manufacturer likely reaches the lower price point. 

It doesn’t contain any color enhancers, like carotenoids or spirulina, so if you’re looking for color development in your koi, this is not the food for you.

Features: 

  • 35% minimum protein content and 5% minimum fat content
  • Floating pellets
  • Multiple size bags available so easy to test if Koi like it

Pros: 

  • Price per pound is very affordable. Good value.
  • Some users report similar growth and color eating this food as compared to more expensive brands

Cons:

  • Less flavorful for Koi (fish will often eat other foods first)
  • Can cloud water if overfeeding occurs

Best Probiotic: Blue Ridge Probiotic Plus

Blue Ridge Probiotic Plus Koi Food is focused on boosting Koi immunity and safeguarding against disease. To support these goals, it includes probiotics, elevated vitamin C, and montmorillonite clay. Primalac and vitamin C increase fish immunity while montmorillonite clay helps with digestion and overall health. 

Features: 

  • Minimum 32% protein and 5% fat content
  • Available in different sizes
  • 100% satisfaction guarantee
  • Floating pellets

Pros: 

  • Helps boost immunity, disease resistance and good digestion.
  • Enhances coloring and helps replace essential minerals and trace elements fish need.
  • Resealable containers that keep food fresh up to a year
  • Good value for large bucket of food

Cons: 

  • Some users reported their koi didn’t enthusiastically eat this food
  • Unclear if koi are actually healthier because of eating this food

Best Day-to-Day:Hikari Staple Floating Pellets

This premium pellet food from Hikari is daily diet food for koi in warmer water temperatures. The balanced ingredients support growth and efficient nutrient utilization. This food contains a minimum protein content of 34% and a minimum fat content of 3%.

Features: 

  • Floating pellets
  • Ziplock closure for easy reseal
  • Includes Vitamin C for increased immunity
  • Respected Japanese brand

Pros: 

  • Good value
  • Koi gobble it up
  • Users report good growth and colors with this food

Cons: 

  • Some users reported cloudy water after using this food

Good Day-to-Day Alternative: Mazuri Koi Pond Nuggets

Mazuri Koi Pond Nuggets Fish Food are designed to be complete nutrition for your koi.  They are floating nuggets so you can observe your fish when they come to the surface for feeding time. Mazuri Koi Pond Nuggets are made in the USA from sustainable fishmeal, making them an eco-friendly choice.

Features: 

  • Floating nuggets
  • Minimum protein content of 33% and minimum fat content of 2.5%

Pros: 

  • Good value
  • Sustainable fishmeal source used
  • Stabilized source of vitamin C ( improves shelf-life and water stability)

Cons: 

  • Some koi not enthusiastic about the flavor
  • Pellet size might be too small for large koi

Best for Color: Hikari Gold

This premium pellet food from Hikari is focused on color saturation in your Koi. As such, this food contains both Spirulina and Krill, concentrated sources of carotenoids, to ramp up the color of your koi. The food is recommended for fall and winter primarily because of the relatively low protein content.

Features: 

  • Minimum protein content of 35% and minimum fat content of 3%
  • Contains carotenoids and Vitamins A, C, D3 and mineral mix for overall color and health development

Pros: 

  • Koi enthusiastically eat this food
  • Users report vibrant colors after consistently feeding this food

Cons: 

  • High ash content (17%) which can create unnecessary waste in your pond and contribute to algae growth
  • Bags are not resealable

Best for Color – Budget: Tetra Pond Koi Vibrance

This is a good budget friendly color-enhancing food from TetraPond. It is designed for feeding koi in water temperatures that are over 50 degrees Fahrenheit. The food has a protein content of 31% that is derived primarily from fish meal. This is slightly lower than the recommended protein concentration so if you’re feeding this food, make sure to supplement with other sources of protein.

This fish food contains soybean oil as an abundant fat source. In total, the food is roughly 5% fat, which aligns with most other mainstream koi foods.

Features: 

  • Floating sticks
  • Contains 31% minimum protein content and 5% minimum fat content
  • Vitamin enriched with natural color enhancers to make your koi more colorful
  • Shelf life is up to 1 year

Pros: 

  • Floating sticks soften in water, making easier to koi to eat
  • Great value for color-enhancement food

Cons: 

  • Zipper on bag breaks easily so might need alternative storage container
  • Food can soften too quickly if fish are slow eaters (not as dense as more expensive food)

Koi Food FAQs 

How do I know if my koi fish is hungry?

Koi fish that are hungry will come to the surface and eat voraciously. If they don’t do that, they are communicating that they are too cold, too warm, or, for some other reason, are not hungry. So feed light if you see those signs. As a koi keeper, you will soon begin to understand the feeding signs.

In general, as long as your koi are growing from ½ – 1 inch per month, it is a good sign that they are being fed correctly.

Can koi fish eat bread?

Foods that are high in carbohydrates, like bread, should be avoided. White bread should especially be avoided. Bread is difficult for koi to digest. Other examples of problematic foods include peas and corn.

Do koi fish need to be fed every day?

As a general rule of thumb, you should feed your koi at least once a day. You should only provide the amount of food that they can consume within 5 minutes. If your fish continue to exhibit signs of hunger, you can increase the frequency up to three times daily, if they’re rapidly consuming all of the food provided.

Overfeeding is a common issue that should be avoided, as it is bad for the health of the koi and reduces the water quality.

How long can koi fish go without food?

During the winter, koi can go through the entire winter without eating, as they can go into a state of hibernation. If the water is below 40 degrees Fahrenheit, it is not recommended to feed your koi.

During the summer, koi can easily go two weeks without being fed their proper koi foods. They will consume small amounts of bugs, algae, and anything else they can find in the water to eat in order to take in some calories.

Can koi fish eat dog food?

Technically, yes, you can feed your koi dog food. However, dog food is not specially formulated for your koi so you should avoid making this a major component of their diet. Overfeeding dog food to your koi will not help with their growth or color development, as they won’t be receiving the specialized nutrients they need for growth. 

Dog food is generally high in protein which could be good for koi, depending on the season. However, if the protein content is too high, your koi might have difficulty digesting the protein, which could create digestive issues.

Can Koi eat rice?

Yes, Koi can eat rice. However, starchy foods like rice should be fed in moderation. When feeding carbs, whole grains are best. For example, whole-grain wheat bread is better than white bread and wild rice or brown rice is better than white rice.

Can Koi eat banana?

Yes, bananas are a great treat for koi. They are soft and easy to consume and contain B vitamins, magnesium, potassium, and folate. They’re a nutrient-dense snack for your fish. They are best cut into smaller chunks so that they float more easily. Smaller chunks are also easier for your koi to swallow. 

Can koi fish die from overfeeding?

Technically, yes. However, death from overfeeding would require both intense feeding schedules and ignoring the growing waistlines of your fish. There would be many stages before death would occur, including the increasing girth of the fish, a decrease in their activity levels, and an increase in the waste they’re producing. Additionally, the fish would likely begin to have issues with excess accumulation of fat around their internal organs, which can be life threatening. Once this stage had been reached, it would be feasible for koi to die.

However, it is very unlikely that a single large feeding session will kill your fish.

What do Koi Fish Eat? What are the best koi food options?

Koi are some of the most beautiful and delightful fish to keep. They bring joy to their owners with their beautiful colors and social behavior. However, they have specific food requirements that are important to understand for optimal health. 

Our number one recommendation for day-to-day food is Hikari Staple Floating Pellets. If koi owners want to grow their fish, we recommend Hikari Saki Growth Pellets and if they’re interested in color enhancement, Hikari Gold is the way to go. Hikari is a well-known, respected, and high-quality koi and goldfish food producer so you’re in good hands when you make this choice.

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