Skip to content

Buying koi

By the koi.wiki editorial team · Updated

Key facts: Buying koi involves choosing a reputable dealer or breeder, understanding age, size and origin terms, judging price against quality factors, and quarantining new fish before introducing them to an established pond.[1][2]
Nishikigoi (錦鯉) can be purchased from specialty koi shops, breeders, retailers, breeder-retailers, home improvement and pet stores, or online, according to the All Japan Nishikigoi Promotion Association (JNPA).[2] The JNPA recommends buying from retail stores affiliated with the association to help ensure quality and health standards, noting that online sales carry potential disease concerns.[2]Price, age, size and origin all factor into a purchase decision. According to the US importer Kodama Koi Farm, the five major factors affecting a koi's value are size, beauty, sex, bloodline and rarity.[1] The JNPA notes that koi are sold from as little as 500–1000 yen for beginners up to historic auction prices in the hundreds of millions of yen for exceptional show fish.[2]

Japanese, domestic and imported koi

Buyers often weigh whether to purchase Japanese, domestic, or imported koi. According to Kodama Koi Farm, Japanese koi are bred by breeders in Japan with generations of passed-down lineages and practices, and are considered the most genuine and highest quality, tending to grow bigger and older than other koi.[1] Domestic koi are bred by breeders outside Japan, sometimes using broodstock originally imported from Japan.[1] This topic is explored further on the page about Japanese, domestic, Israeli and Chinese koi.Bloodline is described by Kodama Koi Farm as a major factor in how a koi will look and grow as it matures, regardless of its current appearance, and buyers are encouraged to ask dealers about a fish's breeder and bloodline history.[1][6]",

Age, size and variety

Koi are counted in age terms distinct from human years: a koi is called tosaigyo from hatching to about one year old, and nisaigyo after one year; the JNPA recommends nisaigyo for first-time owners.[2] Kodama Koi Farm similarly notes that Tosai koi are one-year-old fish, while Tategoi refers to koi of any age judged to have great potential, and that younger fish typically cost less.[3] More detail on these terms is covered on the page about age terms: tosai, nisai, sansai and yonsai.Pond and filtration capacity, not just pond size, should guide how many and how large a koi to buy, according to Kodama Koi Farm.[1] Jumbo koi are described by the same source as typically longer than 24 inches (61 cm) and weighing up to 40 pounds (18 kg).[3] The JNPA notes that koi exceeding one meter in length have been bred through selective improvement, with Mujimono varieties tending to grow largest, and that growth can be limited or encouraged by the size of the container or pond a koi is kept in.[2]The JNPA states there are over 140 varieties of Nishikigoi, with new varieties emerging almost every year in Niigata, while shows officially categorize fish into 22 varieties recognized as Japanese Agricultural Standards since November 2022.[2] Kodama Koi Farm, by contrast, describes over 100 officially recognized varieties.[3] Readers can compare variety groupings on the koi varieties page and the classification page.",

How much do koi cost?

According to Kodama Koi Farm, bloodline, beauty (body shape, quality and pattern), variety, rarity, size and age are the primary factors determining a koi's price, with larger and older fish generally costing more.[3] The source suggests beginners typically spend $45 to $150 per koi when starting with smaller, younger fish or mixed packs, and states that Kodama Koi Farm offers quality Japanese koi options for under $500 as a middle price range.[1][3]At the high end, the JNPA cites an auction record of 230 million yen for a Kohaku (9 years old, 101 cm) bred by Sakai Koi Farm in Hiroshima.[2] A secondary news source, the Daily Mail, reported that the same fish, named S Legend, sold for 203 million yen (reported as roughly £1.4 million) to a buyer identified as Miss Yingying from Taiwan, citing British koi dealer Tim Waddington.[4] Further pricing detail appears on the how much do koi cost page and the record koi prices page.",

Quarantine before stocking

Kodama Koi Farm strongly recommends quarantining every newly purchased koi before adding it to an existing pond or aquarium, describing a separate quarantine tank as a necessary tool for koi keepers.[5] Its suggested setup includes a tank of 100–300 gallons, filtration or at least aeration, a water temperature of 72°F or above, and salt added to a 0.3% concentration (3 pounds of salt per 100 gallons of water).[5] The source also states that even dealers who test for koi herpesvirus (KHV) should not be over-trusted, and that only the buyer can protect an existing collection by quarantining new arrivals.[7]Regarding KHV specifically, Kodama Koi Farm recommends a quarantine period of at least four weeks to help identify potential carriers, alongside limiting pond access and buying only from trusted sources that perform KHV testing.[8] The farm states it cannot guarantee koi are "KHV free" but describes them as "KHV tested," and advises asking a dealer where a koi originated, whether the supplier tested for KHV, and the water temperature and duration of quarantine used.[9]General extension guidance on fish stocking recommends "tempering," or slowly acclimating fish to changes in water temperature, allowing at least 20 minutes of gradual adjustment for every 10°F of difference, and floating sealed shipping bags in receiving water until temperatures equalize before release.[10] It notes that fish stressed by transport or improper acclimation may sink or swim weakly, and that stress-related disease outbreaks can appear hours to days after stocking.[10] More detail is covered on the quarantine page and the shipping, bagging and acclimation page.",

Selecting individual fish

Kodama Koi Farm advises evaluating color balance, body shape and behavior, and matching a prospective purchase to a buyer's goals, whether pond enjoyment, family tradition or show competition.[1] It notes that koi intended for shows do not need to be the largest fish in a pond to become grand champions, since shows judge within size categories and weigh color, pattern and body conformation as well.[1][6] Buyers interested in competing can review the koi grading and quality page and the how koi are judged page.",

Entries in this section

Common questions

Where can koi be purchased?
According to the All Japan Nishikigoi Promotion Association, koi can be bought from specialty koi shops, breeders, retailers, breeder-retailers, home improvement stores, pet shops and online, though the association recommends buying from its affiliated retail stores.[2]
How much should a beginner spend on a first koi?
The US importer Kodama Koi Farm suggests beginners typically spend $45 to $150 per koi when starting with smaller, younger fish or mixed packs before investing in higher-quality fish.[3]
Do new koi need to be quarantined?
Kodama Koi Farm strongly recommends quarantining every new koi, suggesting a tank of 100–300 gallons, a water temperature of at least 72°F, and salt at 0.3% concentration, with a KHV-focused quarantine of at least four weeks.[5][8]
What is the difference between Japanese and domestic koi?
Kodama Koi Farm describes Japanese koi as bred in Japan with generations of lineage and considered the highest quality, while domestic koi are bred outside Japan, sometimes from broodstock originally imported from Japan.[1]
How many koi varieties exist?
The JNPA states there are over 140 varieties of Nishikigoi, officially grouped into 22 show categories recognized as Japanese Agricultural Standards, while Kodama Koi Farm cites over 100 officially recognized varieties.[2][3]

References

  1. ^ How to Select Koi - Which are Best to Choose for My Pond?. Kodama Koi Farm (koi dealer). kodamakoifarm.com/how-to-select-koi-for-pond/. Retrieved November 2026.
  2. ^ Q&A - All Japan Nishikigoi Promotion Association. All Japan Nishikigoi Promotion Association. jnpa.info/en/qa/. Retrieved November 2026.
  3. ^ How Much Do Koi Fish Cost? Koi Pricing Guide for USA. Kodama Koi Farm (koi dealer). kodamakoifarm.com/how-much-do-koi-fish-cost/. Retrieved November 2026.
  4. ^ World's most expensive Koi Carp is bought for £1.4 million - £1m more than previous world record | Daily Mail Online. dailymail.co.uk. dailymail.co.uk/news/article-6240401/Japanese-koi-fish-sells-record…. Retrieved November 2026.
  5. ^ How To Care For Your Koi Fish After Receiving It - Kodama Koi. Kodama Koi Farm (koi dealer). kodamakoifarm.com/koi-care-after-receiving/. Retrieved November 2026.
  6. ^ Preparing for Koi Competition and Tips for Winning Koi Shows. Kodama Koi Farm (koi dealer). kodamakoifarm.com/koi-show-competition-tips-preparation/. Retrieved November 2026.
  7. ^ Koi Quarantine Tank Setup & Procedures. Kodama Koi Farm (koi dealer). kodamakoifarm.com/koi-quarantine-tank-setup-procedure/. Retrieved November 2026.
  8. ^ Koi Herpes Virus (KHV): In-depth Exploration of the Deadly Virus to Prevent & Manage. Kodama Koi Farm (koi dealer). kodamakoifarm.com/koi-herpes-virus-khv-disease-guide/. Retrieved November 2026.
  9. ^ Safely Managing Japan KHV Outbreak with New Processes and Technology at the Farm. Kodama Koi Farm (koi dealer). kodamakoifarm.com/managing-japan-khv-outbreak/. Retrieved November 2026.
  10. ^ UF/IFAS EDIS FA013: Fish Fingerlings: Purchasing, Transporting, and Stocking. University of Florida IFAS Extension (EDIS). ask.ifas.ufl.edu/publication/FA013. Retrieved November 2026.