Koi fish are beautiful decorative fish that live in outdoor ponds.
Many new or prospective koi fish owners wonder how feeding these peaceful fish works.
So what do koi fish eat?
This guide will cover everything you need to know about feeding koi fish, including what they eat, how to feed them, and common feeding issues owners have.
What Do Koi Fish Eat?
Koi fish are omnivores, meaning they can eat most things like humans.
Koi will eat plant-based materials such as algae or plants and animal-based materials like insects.
Koi can also consume human food, such as rice, cereal, shrimp, and watermelon.
What Kinds of Foods Do Koi Fish Eat Naturally?
Koi fish are a highly domesticated species, but many wild koi are still roaming the world’s waters.
In the wild, koi fish primarily eat anything they can find.
The fish will try to find higher-protein food sources, such as insects and insect larvae, but edible plants like algae are also a big part of their diet.
Types of Koi Fish Food
There are several different types of koi fish food available for domesticated species.
Fish Food (Fish Flakes and Pellets)
Fish food, which comes in the form of flakes and pellets, is one of the most popular and common food options for all species of domesticated fish, including koi fish.
Like other pet foods, the pellets or flakes are a well-balanced combination of carbs, protein, and fat formulated specifically for koi fish.
Many fish enthusiasts opt to make their own fish food at home.
This option is popular for those looking to cut down on food costs or avoid trips to the store.
Recipes for homemade koi food consist of a mixture of carbohydrate sources (wheat germ, bread), protein sources (krill, shrimp), and healthy fat sources (flaxseed oil, fish oil).
These ingredients are then blended with fruits and vegetables.
Frozen koi fish food is similar to frozen or frozen-dried treats available for koi fish.
The ingredients are frozen to preserve freshness.
Frozen food should always thaw out before serving it to your koi.
Live food can satisfy your koi fish’s need for protein while also livening up the pond.
Many owners pick up live insects and insect larvae from their local pet store or bait shop.
Can a Koi Fish Eat Human Food?
Koi fish are omnivorous, just like humans, so there are many human foods that koi fish can eat and enjoy.
What Kinds of Human Food Can a Koi Fish Eat?
Here are some popular human foods for koi fish.
- Watermelon: Koi fish are huge fans of watermelon. Watermelon is an excellent source of fiber for your koi.
- Spinach: Koi fish enjoy leafy greens, but spinach is the most nutrient-dense option for the fish.
- Oranges: Orange slices are a great source of Vitamin C for your pets, and the fish enjoy the soft texture.
What Is the Best Type of Food for Koi Fish?
Many koi fish owners opt for a mixture of the options we’ve covered.
A koi fish will be perfectly healthy and happy with just pellets and live plants in their pond, though the extra effort of frozen treats or a homemade meal can be worth it.
How To Feed a Koi Fish
Koi fish are very gentle, so they typically let humans hand-feed them.
A new koi fish may be a bit skittish initially, so you can throw a small handful of pellets into the water.
Once the pellets are eaten, you can throw another handful and repeat.
Never throw a giant handful, as the pellets may go uneaten and mess with the pond’s water quality.
How Often Do You Feed a Koi Fish?
Koi fish should be fed two to four times per day.
At each feeding, the fish should be allowed to eat as much as they can in five minutes.
Koi typically eat more when the water is warmer and less when the water is colder.
How Long Can Koi Fish Go Without Eating?
Koi fish’s eating habits change with the seasons, but the species can survive up to two weeks without food.
The fish eat more in the summer and less in the winter, as their metabolism slows in the cold weather.
A koi fish can eat as many as five meals a day during the summer, but they stick to about two meals per day during the winter.
Can You Overfeed a Koi Fish?
Like any animal, koi fish can be overfed.
As a general rule, you should only feed your koi fish as much as they can eat in five minutes.
Limiting the feeding to five minutes ensures the fish doesn’t overeat.
In addition, koi fish should only be fed between two and four meals daily.
Help, My Koi Fish Isn’t Eating
If you’ve noticed that your koi fish isn’t eating, you may be alarmed.
Below are a few reasons why your fish isn’t eating and how you can help them.
Reasons Why A Koi Fish Isn’t Eating
Here are some of the most common issues that cause a fish to not eat.
Koi fish eat less when the pond water is at a lower temperature.
Since koi fish live in outdoor ponds, this is a natural part of changing seasons.
Koi fish usually eat only one or two meals per day during winter.
Koi fish eating less during winter is a regular aspect of the fish’s feeding cycle.
If it’s not winter, check your water temperature to ensure it has not accidentally dipped.
Koi fish require an oxygen level of 6 parts per million to survive.
This oxygen also helps the fish’s natural body processes, including digestion.
If a koi fish doesn’t receive enough oxygen, this can lead to serious consequences, including death.
Low Water Quality
If a koi fish doesn’t have high water quality or doesn’t feel comfortable with the water, it will likely stop eating.
Chemical buildup, filter issues, and leaching are the primary causes of water quality issues in koi ponds.
Disease or Illness
If the above issues are not present, you may be in an unfortunate situation where your koi fish suffers from a disease or illness.
The most common signs that a koi fish is sick are:
- Not eating
- Gasping at the pond surface
- Isolating themselves
If your koi fish is displaying the above symptoms consistently, you should consult a veterinarian.
Your local veterinarian will direct you to a vet specializing in fish if necessary.
What To Do if a Koi Fish Isn’t Eating
If your koi fish isn’t eating, you should check the water temperature, oxygen level, and water quality to ensure it isn’t a straightforward environmental issue.
If none of these issues are present, you can consider the type of food you are feeding them and try something new temporarily.
You should consult a veterinarian if your koi fish shows any signs of distress or illness or if the above methods don’t work.
Frequently Asked Questions
Here are some frequently asked questions regarding koi fish and feeding.
Can you feed a koi fish at night?
It’s alright to feed koi fish at night, though it’s recommended that owners stick to a daytime feeding schedule.
Koi fish are active at night, but they tend to stay near the bottom of the pond during this time.
Do koi fish eat worms?
Yes, koi fish eat worms! Bloodworms and earthworms are the best options for koi fish and are often given as treats.
Live worms are best, as their nutritional content is higher than freeze-dried options.
Koi fish are omnivores, so there are many options for feeding these decorative fish.
Whether you decide on pellets or homemade food, remember that mixing things up is always a good idea, so your koi fish stay vibrant, happy, and healthy.
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