Quick” Expedited 21-Day Koi Quarantine Procedures

Many new koi hobbyists seem surprised when we strongly recommend they quarantine all new koi additions before adding them to their main pond.  Our recommendation applies regardless of source, because in our experience comon koi parasites can be found during scoping in virtually any established pond.  Many hobbyists also seem unclear about what it actually takes to build a proper quarantine tank (QT), so we have created this page as a resource to help guide hobbyists through the koi quarantine process. 

Why is quarantine recommended for koi?

A common misconception is that quarantine is not required if new koi additions appear to be healthy and/or if strict quarantine procedures have already been completed by your koi dealer.  Nothing could be further from the truth.  Getting chased around with a net and transported in a bag can be very stressful for koi, and this creates a very dangerous opportunity for parasites to strike.  Regardless of how healthy and vibrant your existing koi may seem to be, these deadly parasites are ALWAYS present in virtually any established koi pond.  Because they are not overly stressed due to recent handling and transport, your existing koi fish have likely managed to find a peaceful “co-existence” with the parasites already present in your pond.  It is not possible to permanently eradicate all parasites from any koi pond; therefore, following sound quarantine procedures for all new koi additions is critically important to ensuring optimal koi health.

What is a quarantine tank (QT)?

A quarantine tank (QT) is a separate tank used to temporarily care for new koi additions before adding them to your main pond.  A QT does not need to be fancy or expensive.  Used Rubbermaid stock tanks work great for this purpose and can be easily found at affordable prices from a variety of sources.  In most cases, a 100-gallon stock tank would make an excellent QT while also making dosing a lot easier when applying treatments.  You will also need a small pump and filter setup to keep the water in your QT clear and healthy during the quarantine process.  Use an aerator pump to keep the water in your QT well-oxygenated. Be sure to cover your QT with pond netting to prevent new koi from jumping out.    

How long should I quarantine new koi before adding them to my pond?

We highly recommend a MINIMUM quarantine period of 4-6 weeks for all new koi additions; however, we realize this is not always feasible.  Many hobbyists also do not wish to wait very long before they get to enjoy seeing their new fish swimming in their ponds. So we have taken the time to publish “quick” 21-day koi quarantine instructions to help encourage all koi keepers to complete some level of quarantine to help ensure the long-term health of their koi.   

What treatments should I apply during quarantine?

Besides a dedicated QT, you will also need three different products to successfully complete our “quick” 21-day koi quarantine process.  We consider these items to be absolute MUST-HAVES for any serious koi keeper.  In other words, if you do not already have these items readily available then you should order them today! 

Required MUST-HAVE Treatments:

  1. Salt
  2. Praziquantel (Prazi)
  3. Potassium Permanganate (PP)

Why do I need these treatments?

At proper dosage, salt alone can eradicate most common koi parasites all by itself. Unfortunately, some parasites have developed a resistance to salt so additional treatments are often required. Praziquantel (Prazi) is used to treat salt-resistant flukes while potassium permanganate (PP) is used for salt-resistant costia. You can learn more about flukes and costia on our Koi Health page.

Where can I find these treatments?

You can find praziquantel and potassium permanganate on Amazon. Both are sold under many different brand names, so just get the cheapest options you can find.  Salt can be easily found almost anywhere.  As long as the specific salt you select is pure (no additives) then it should work just fine.  We purchase salt ourselves in big 40-pound bags, which can be found at our local Home Depot for around $8 per bag.    

How do I prepare my QT for new koi arrivals?

We recommend maintaining a consistent salinity level of .04% in your QT. To achieve .03% salinity, simply add 3 pounds salt per 100 gallons of water.  Using a digital salinity meter will allow you to easily monitor exact salt levels in your QT.  You can find digital salinity meters easily on Amazon for around $30.  Be sure to add dechlor to your QT during partial water changes and as needed to prevent ammonia spikes.  Add additional salt as needed to maintain consistent .03% salinity level throughout the quarantine process.  Closely inspect all koi in your QT on day 21.  If no issues are found, then release your new koi into your pond.  If any issues are detected, then do NOT release new koi into your pond and extend quarantine period as needed until the issues are resolved. You will also need to use a digital gram scale to measure proper dosages for prazi and PP during treatments. If necessary, use an aquaruim heater to maintain a consistent water temperature between 70°F – 72°F throughout entire quarantine process.

Salt Dosage and Treatment Instructions:

Maintain consistent .03% salinity level in your QT at all times. Be sure to add additional salt as needed to your QT following partial water changes to maintain this same .03% salinity level throughout quarantine process.

Prazi Dosage and Treatment Instructions:

Use 1 gram prazi per 100 gallons water. Mix prazi well with water in a shaker cup. Once mixed, pour directly into your QT. Prazi will not impact your filter, so there is no need to turn off your pump and/or bypass filter during prazi treatment.

PP Dosage and Treatment Instructions:

ALWAYS have some hydrogen peroxide nearby BEFORE doing any PP treatment! Use 4 ounces hydrogen peroxide per 100 gallons water to deactivate PP immediately. Also be sure to turn off your pump and/or bypass your filter because PP will kill all beneficial bacteria in your filter! Sufficient aeration is also VERY important during PP treatment so keep your air pump running and closely monitor koi in QT during PP treatment for any signs of stress. If any issues are detected (fish jumping, swimming frantically, gasping for air, etc.) immediately add hydrogen peroxide to QT. Use 1 gram PP per 100 gallons water. Mix PP well with water in shaker cup. Once mixed, pour directly into your QT. During PP treatment the goal is for water to your QT to remain purple for up to 4 hours. Once water color changes from purple to champagne, PP is no longer active and it is safe to turn back on your filter. After completing PP treatment, add 4 ounces hydrogen peroxide to instantly clear water.

“Quick” 21-Day Expedited Koi Quarantine Schedule:

  • Day 1: Complete prazi treatment #1
  • Day 4: Complete PP treatment #1
  • Day 5: Complete 20% partial water change, add dechlor
  • Day 7: Complete prazi treatment #2
  • Day 10: Complete PP treatment #2
  • Day 11: Complete 20% partial water change, add dechlor
  • Day 14: Complete prazi treatment #3          
  • Day 17: Complete PP treatment #3
  • Day 21: Check all koi in QT then release to main pond        

What if I don’t have a dedicated QT?

While strongly recommended, a dedicated quarantine tank (QT) is not a requirement to adopt koi fish from Southern California Koi Rescue.  Regardless of source, if you choose to add new koi additions directly to your main pond then you must understand that your main pond now effectively becomes your QT.  This means you must treat it accordingly.  In most cases, simply adding salt to achieve .04% salinity is sufficient to help koi recover from stress caused during handling and transport.  You should also treat your entire pond for common salt-resistant parasites (flukes and costia), which can be found during scoping in virtually any established backyard fish pond.  Your existing fish may have already managed to find a peaceful coexistence with these parasites, but your new koi have not, therefore preventative measures are critically important to help ensure optimal koi health.  Maintain this same .04% salinity level for a MINIMUM period of 4 weeks while also treating your main pond with Prazi and PP for salt-resistant parasites.  Three treatments of both Prazi and PP is recommended.  After this protocol has been completed, you can return to your normal pond maintenance schedule. 

We hope you have found this page to be useful. Southern California Koi Rescue is a registered non-profit animal rescue specializing in koi fish and other pond pets. Since 2008 our dedicated volunteers have completed hundreds of large koi rescues throughout CA, NV, and AZ while successfully finding new forever homes for thousands of beautiful living jewels. For those interested, charitable donations can be made via our Donations page.