Quarantine Protocol for Koi Purchased Online

By KoiQuanta Editorial Team|Updated Mar 2026

Buying koi online is convenient and sometimes the only way to access certain breeders or varieties. It's also one of the highest-risk fish acquisition scenarios in the hobby.

When you buy from a local dealer you trust, you can visit the facility, see how fish are kept, ask about quarantine history, and assess the operation. When you buy online from a seller whose tanks you've never seen, you're making significant health assumptions based on photos and seller reputation.

I've bought online. I've also received fish from online sellers that arrived with parasites, bacterial infections, or conditions that were clearly developing before they shipped. The online purchase protocol needs to be more rigorous than the standard arrival protocol - not less.

TL;DR

That's 12–48 hours in a declining bag environment.
A fish that appeared healthy at shipment can show disease signs within 48–72 hours of arrival.
For online purchases - particularly from sellers you haven't personally vetted - 42 days is more appropriate.
But 42 days is the default for unknown or first-time online sellers.
Contact the seller within the guarantee window (typically 24–72 hours for live arrival guarantees, sometimes extended to 7 days for health guarantees) 2.
Provide photographic evidence of the condition 3.
Provide your arrival condition documentation showing the fish arrived with or without visible symptoms 4.

What Makes Online Purchases Higher Risk

Unknown health history. You have no direct knowledge of the seller's quarantine practices, koi pond water quality tracker standards, or disease history. A reputable seller's word is meaningful - it's not the same as documented records you can verify.

Extended shipping stress. Online koi typically ship via overnight air or 2-day shipping in insulated boxes. That's 12–48 hours in a declining bag environment. Even under optimal conditions, this is a significant stress event. Under non-optimal conditions (temperature swings during transit, carrier delays, rough handling), fish arrive in poor condition.

Delayed disease expression. Some conditions that were subclinical or well-controlled in the seller's established pond environment will express clinically under the immune suppression caused by shipping stress. A fish that appeared healthy at shipment can show disease signs within 48–72 hours of arrival.

No seller-side quarantine documentation. Most online koi sellers don't provide quarantine records. You're getting a health certificate that says the fish appeared healthy at time of sale, not a documented quarantine history.

Adjusting Your Protocol for Online Purchases

Extended Minimum Hold: 42 Days

Standard domestic quarantine is 21 days minimum. For online purchases - particularly from sellers you haven't personally vetted - 42 days is more appropriate.

This reflects:

Higher baseline disease risk
Unknown health history requiring full observation coverage
Potentially longer time for stress-suppressed disease to express

If the seller is someone you've purchased from repeatedly with good outcomes and provides some form of health documentation, 30 days may be sufficient. But 42 days is the default for unknown or first-time online sellers.

Treat Them Like Imports Until Proven Otherwise

The protocol for online domestic purchases should closely mirror the Japanese import protocol:

65–68°F quarantine temperature to keep any potential KHV in the expression window
Prophylactic praziquantel course on days 3–5 (flukes are extremely common in fish from unknown sources)
0.3% salt starting within 48 hours of arrival
Daily observations with documented appetite and behavior
Full parameter suite twice daily in week 1

More Intensive Arrival Day Inspection

Because you have no facility visit to inform your expectations, the arrival inspection matters more. After acclimation and before the fish are left to settle:

Count fish against order (discrepancies need to be reported to the seller immediately)
Note arrival bag water temperature (ideally within 5°F of your tank)
Smell the bag water - it should smell like water, not like rot or strong ammonia
Quick visual scan of each fish before releasing them: obvious wounds, white patches, fin abnormalities, unusual coloration
Note any DOA immediately and photograph before discarding

Document this all in your quarantine log. If you're disputing a health issue with a seller later, the arrival condition documentation is your evidence.

Sourcing Risk Hierarchy

Not all online purchases carry equal risk:

Lower risk:

Established Japanese importers with verifiable quarantine facilities
KHV-tested fish from documented testing programs
Sellers who provide quarantine records and health certificates
Sellers whose facilities you've visited or that have verifiable independent reviews from serious hobbyists

Higher risk:

eBay, Craigslist, or Facebook marketplace individual sellers
Sellers who can't answer basic questions about their quarantine protocol
Fish sold as "pond-ready" without quarantine history
Cheap fish from unknown sources

For high-risk sources, consider whether the price savings are worth the disease risk to your collection. One KHV introduction can cost more than the entire lifetime spend on online fish purchases.

Questions to Ask Before You Buy

Before purchasing from an online seller for the first time:

What is your quarantine protocol for new arrivals?
Have your fish been KHV tested? Can you share results?
How long have these specific fish been in your possession?
What is your health guarantee and what does it cover?
Have you had any disease events in the tank these fish are currently in?

A reputable seller will answer these questions directly. Evasive or dismissive responses are a red flag.

Shipping and Arrival Timing

Online koi should arrive during mild weather conditions. Shipments arriving in extreme cold or extreme heat are at elevated risk - temperature swings in transit are stressors, and airlines route packages through distribution centers that may not maintain appropriate temperatures.

Best practice:

Schedule shipment for mid-week arrival (Tuesday or Wednesday) to avoid weekend carrier delays
Confirm overnight or 2-day delivery with live arrival guarantee
Be home to receive the shipment - don't let fish sit on a porch in July or January
Check the tracking obsessively from shipment day forward

When Fish Arrive in Poor Condition

If fish arrive with clearly elevated distress - on their sides, gasping, very pale - your priority is dissolved oxygen. Get them into the prepared quarantine tank as fast as possible. Add an emergency dose of sodium thiosulfate to neutralize any residual chlorine if you haven't pre-treated the tank.

Don't add salt immediately if fish are severely stressed. Wait 24 hours. Give the fish time to stabilize in clean, well-oxygenated water before adding the osmotic load of salt treatment.

Document condition with photos and video immediately on arrival. If you need to claim against the seller's live arrival guarantee, this documentation is essential.

Reporting Health Issues After Purchase

If disease develops during quarantine in fish purchased online:

Contact the seller within the guarantee window (typically 24–72 hours for live arrival guarantees, sometimes extended to 7 days for health guarantees)
Provide photographic evidence of the condition
Provide your arrival condition documentation showing the fish arrived with or without visible symptoms
Note the water parameters at the time disease was observed (to counter the "you killed them with bad water" defense)

KoiQuanta's arrival day entry and daily observation logs provide exactly this documentation in a format you can export and email to a seller or payment processor.

FAQ

How long should I quarantine koi shipped from an online seller?

A minimum of 42 days for unknown or first-time online sellers. Shipping stress suppresses immune function for 72+ hours, which can allow subclinical disease to express over the following week. The longer quarantine window ensures you're observing the fish through multiple potential disease expression timelines, not just the immediate post-arrival period.

What should I look for when online koi arrive?

Inspect the bag water temperature and smell, count fish against your order, and do a quick visual scan of each fish before releasing them into the quarantine tank. Note any DOA, any immediately visible lesions or abnormalities, and document with photos. Arrival day documentation is your protection if you need to dispute a health claim with the seller.

How do I report disease in koi bought online?

Contact the seller within their stated guarantee window, providing photographic evidence of the condition and documentation of your water parameters at the time of observation. KoiQuanta's arrival and observation logs give you timestamped, exportable records showing what condition the fish were in at arrival and what developed subsequently - which is exactly the documentation needed to distinguish transport-related disease from water-quality-related disease.