Standard Koi (Cyprinus rubrofuscus)

Standard fin Koi (Cyprinus rubrofuscus) are the classic pond showpiece: hardy, peaceful, long lived, and endlessly personable once they learn to greet you at feeding time. These are standard grade fish in a mix of reds, whites, oranges, and blacks, each one patterned differently, and at 3 to 4 inches they are the perfect size to grow out in your pond. Come pick your favorites in person, and browse the rest of our freshwater livestock while you are here.

Care Guide

• Pond fish first: koi reach 24 inches or more and live for decades. Plan on a pond of 250 gallons or more per fish long term. An aquarium works only as a temporary grow-out home.
• Coldwater, no heater: comfortable from 50 to 78°F and fully winter-hardy outdoors. In a pond with 18 inches or more of depth they overwinter in Georgia without help.
• Water: pH 7.0 to 8.5, moderate hardness. Koi are forgiving, but big fish make big waste, so generous filtration and regular water changes matter more every year they grow.
• Feeding: omnivorous. A quality koi pellet as the staple, cut back or stop feeding when water temps drop below 50°F since their digestion slows in the cold.
• Growth: expect fast growth in the first two years with space and good food. Standard grade fish often surprise you, and colors keep developing as they mature.

Specifications

Compatibility

Koi are model pond citizens. They mix perfectly with other koi and with single-tailed goldfish like the Sarasa Comet and Shubunkin. Avoid housing them with small aquarium fish, since anything bite-sized eventually becomes a snack, and skip tropical species entirely as the temperatures do not match. If you want a fancier look in the same pond, our Butterfly Koi with their long flowing fins mix in seamlessly.

Recommended Foods & Supplies

• Fishers Koi Diet+, our staple pond pellet for koi
• Repashy Super Gold gel food for treats and cooler-weather feeding

FAQ

Can koi live in an aquarium?
Only while small. A big tank buys you a season or two of grow-out time, but a healthy koi will outgrow almost any aquarium. Plan for a pond.

Will they survive winter outside?
Yes. Koi are fully winter-hardy in our climate. Keep a hole in any ice for gas exchange and stop feeding below 50°F, and they will be waiting for you in spring.

What colors am I getting?
Standard grade koi come in a mixed assortment of reds, whites, oranges, and blacks. Since this is pickup only, you get to point at the exact fish you want in our tank.

How fast do they grow?
With space and steady feeding, expect 6 to 8 inches by the end of the first year and a foot or more by year three.