Quarantine Procedures for Koi
- Rajat Agarwal
- Jan 31
- 5 min read
Updated: Aug 18
A good quarantine procedure for new koi fish involves isolating them in a separate tank and monitoring them for disease. The good quarantine period should ideally be ~3 weeks. We understand that not everyone has a way to quarantine. Because we strongly believe that this should not stop you from quarantining your fish new to your environment, you can rent the equipment from us, please email info@atxkoi.com or text/call 512-850-8782. This is subject to availability as the equipment might already be booked. We are here to help you.
Overview: Quarantining your new fish, especially if they have travelled a long-distance, is very important because being in a small bag getting jostled around during the journey, in their own poop-water can cause high-stress along with ammonia spikes. Bacteria are opportunistic and a high-stress situation is a perfect opportunity to infect the fish resulting in Aeromonas, Columnaris or other diseases. Parasites that may have travelled with the fish can also start to show infections.
Use this procedure to treat the Koi so the risk of infection for the rest of your existing fish is minimized. We understand it is not practical for most owners to have an entire separate system just for quarantining. Call us as we are happy to help and may be able to quarantine your fish for you, depending on the availability of our quarantine tanks.
Quarantine tank design:
List of items:
Large tank or tub that can hold 50-300gallons of water.
Small pump about 600gph (larger is ok/better).
Small filter (match with pump), ideally with UV on/off switch
Any gloves and face mask (find on Amazon or Walmart - it's cheaper).
Small aerator (aquarium aerator will work, but match to the volume of water). You can use a CAS1
Pond salt (you can also use "naturally evaporated" water softener salt if you can find it)
Medicine to treat the fish for parasites, bacteria, flukes, ich, fungus etc. You can get MinnFinn here
Water test kit like the API Master Test Kit.
Salinity meter (find one on amazon- it's cheaper)
Water thermometer (find one on amazon- it's cheaper)
Patience
Quarantining procedure:
Set-up:
Place the tank away from your main pond so water can't splash between them. Set up the aerator and water pump.
Set up aeration, pumps and filters. Add water and de-chlorinator. Ideally, this should be done a week in advance of your fish arriving.
Adding bacteria will help kick start your quarantine tank's water stability.
(optional but recommended) add pond-salt to create a 0.3%-0.4% concentration in your tub. See table and how-to in the detailed section below.
Float Koi bags in the Quarantine tank’s water for 15-20minutes. This allows the water temperature in the bag to equalize with the water temperature of the quarantine tank so the koi can used to the new water temperature.
Do not mix the water the fish came in, with the water in the Quarantine.
Then release the fish slowly in to the water so they can get used to the pH level and water chemistry.
Add pond salt to create a 0.3%-0.4% concentration in your tub. Use our concentration calculator to figure out how much pond-salt should be added.
Mix the salt in a bucket of de-chlorinated water with proportions shown in the table below. Mixing salt can take 15–60 minutes.
Add the salt water solution to the quarantine tank.
Measure the concentration in the quarantine tank with your salinity meter
Concentrations higher that 0.5% are not recommended. This is potentially dangerous (damage gills and kidneys, introduce lethargy, increase stress, etc.), and might even be fatal.
Ideally, the quarantine tank water temperature should be between 65–78°F. (ideal is 70°F). Worst case, try to keep is below 85°F
Leave the fish alone for 2-3 days
Do not feed the fish during this time.
After 3–5 days, use treatments MinnFinn (1hr treatment ), or optionally separate treatments if you like.
Wear gloves and face-mask while using treatments. When using these treatments mentioned below, it's best to shut off your pump, UV and filters. Leave your aerator on though.
It is really important to treat your new fish for for Parasites+ Fungus+ Flukes+ Bacteria. While Flukes are a type of parasite, broad parasite treatments are usually not effective in treating flukes.
We recommend MinnFinn as this is a treatment that can treat most topical bacteria and parasites in one treatment. MinnFinn disease treatment (available on our site). can be used with this salt-solution. This treatment allows you to treat your Koi with a one hour treatment that treats all bacteria, parasites, fungus and flukes (see application details on our site). It's a 2-part treatment, which comes with a neutralizer so you stop the treatment after one hour. This will get rid of, and therefore minimize infections in the main pond. Note- (MinnFinn was awarded Pond Trade Magazine Product of the year award 2009).
However, instead of MinnFinn, you can use separate treatments if you prefer, like Microbe Lift-Broad Spectrum (available on our site), Terminate, Koi Prazi, MedZyme, Ich-X etc.
See instructions on the bottle for concentration and technique to add the treatment. MinnFinn needs to be neutralized after an hour.
Turn on your pumps, UV and filters back on after 4-5 hours. Leaving them off for this long just and insurance for the medicine to work and/or be neutralized.
Note- for any treatments, best to follow instructions as written.
Measure your water parameters daily. If your water parameters don't balance after water changes, try to use appropriate water-parameter balancing treatments.
Ammonia and nitrites should be at 0ppm ideally (certainly not higher than 0.25ppm).
Monitor the koi daily watch for symptoms:
Red-eyes, flashing, veins, tail rot, yellowing, ulcers, redness on the skin, erratic swimming, spots on any kind.
If disease is found during quarantine, please treat the infected fish.
At this point you have completed a "quick quarantine". We sill recommend additional monitoring as some bacteria may be resistant and not show till later.
Monitor your fish in the quarantine tank for another 2 weeks.
If your parameters swing to the higher side, do water changes. Add the salt to bring the salt-levels back up, and stop feeding for a few days.
That's it! Provided your fish are all healthy, you can then move your fish to your main pond.
Post Quarantine Procedures:
After the fish are transferred, drain and dry the tank.
After treatment we recommend that you should treat the Quarantine tank itself and everything used with it, with a mild bleach solution (either 1 cup per 1000gallons) and then leave it to dry for a few days to get rid of the chlorine. Wear gloves and face-mask while using bleach. Bleach should be plain, without any additives. Do not mix bleach with soap or other cleaners/additives. This cleaning procedure depends on the type of disease found so we highly recommend researching this topic more.
Please email info@atxkoi.com or text/call 512-850-8782 if you need help.
