Calming, Colorful Pets: Koi Fish Care 101

If you’re looking for a pet that brings a sense of calm and serenity into your life, consider raising colorful, beautiful koi fish. They are fun and hardy fish for a backyard pond, tank or indoor aquarium.

But before you bring any koi home, there are a few things you should know about these fish.

Koi are a colored variety of the Amur carp that originated in China as a meat fish, but in the 1820s Japanese fish enthusiasts started breeding them for their bright colors. Now, koi symbolize luck, prosperity and good fortune.

Bag of Mazuri® Koi Platinum Ogata food.

Some koi have lived for over 200 years; however, most have a lifespan of 30 to 50 years. It’s not unusual for Japanese families to pass down valuable koi as a family heirloom.

High-quality koi can sell for thousands of dollars. But you can buy one from a reputable supplier from $20 to $50 or more.

Here are a few more koi facts to consider before you purchase one – or purchase many to start your new pond:

  • Koi grow to an average of 3-feet long.

  • They’re susceptible to sunburns so if they are outside, make sure to have shade. 

  • Koi get to know the individuals feeding them and can be trained to eat food from your hand.

  • Goldfish and koi fish are cousins. They can be raised together.

  • Koi fish are most active at dusk and dawn.

  • Feed only what your fish will eat in 5 minutes, otherwise the food that is left will breakdown and decrease your water quality.

Getting started with koi fish

One of the most important care decisions is where your fish will live. Young koi can be kept in an indoor aquarium, but koi grow very quickly and will eventually need a larger aquarium or tank. Many koi owners create beautiful backyard ponds to enjoy their colorful pets.

Ponds require ongoing maintenance but provide hours of peaceful enjoyment. If you choose this option, consider purchasing a heating system to prevent winter freezing and a filtration system to clean and circulate the water. Your pond will also need shade from trees or overhead covers to keep the water temperature stable. Finally, create a pond with steep sides or nets to keep out predators.

Many koi owners create water gardens in their koi ponds using plants like water hyacinth, water lilies, cattails and floating pondweed.

Choosing a koi fish

The type of koi to purchase is another vital decision. Koi are prized for their vibrant and bold colors and patterns. Though available in a rainbow of hues, the most common koi fish colors are orange, red, yellow, blue, white, cream and black. Their distinctive markings make it easy to quickly recognize and name individual fish and observe their unique personalities.

There are about 15 groups of koi and dozens of varieties, including:

  • Kohaku (white-skinned with large red markings on top)

  • Asagi (blue net-like pattern on the back)

  • Tancho (white with a single red dot on the head)

  • Yamabuki Ogon (solid, metallic yellow)

 New, colorful varieties are continually bred.

Maintaining vibrant colorful koi fish

The beautiful koi colors and patterns are the result of years of careful breeding programs. Early breeders selected naturally occurring mutations in Amur carp to breed new colors into the species. If decorative koi are released into nature, they lose their distinct colors and patterns within a few generations.

While genetics play a role in koi colors and appearance, their habitat, water quality and feed also contribute to it. Top breeders rely on good bloodlines and high-quality fish food with color enhancers to help koi colors remain bright throughout their lifetime.

Look for a koi food that contains optimum nutrition, as well as color enhancers like spirulina algae and carotenoids for vibrant coloration and a source of pigmentation.

Mazuri® Koi diets are a complete feed fortified with vitamins and minerals, so no fish supplements are needed. They come in a variety of specialized shapes, sizes and textures for all your koi feeding needs. Plus, Mazuri® koi food particles float, which encourages your fish to come to the surface so you can enjoy them even more and to allow you to monitor their intake to reduce the risk of overfeeding, which will negatively influence your water quality.

Raising koi is a rewarding and fun pet experience. If you have questions about your koi’s health or nutrition needs, ask our experts. Or, connect with other koi fish enthusiasts on the Mazuri Facebook page.