Koi are large fish that generally do well in large pond style enclosures.
Due to this, keeping adult koi in a tank is largely believed to be unethical and cruel.
Still, having a prepared tank on hand to act as a holding or quarantine tank is still a good idea in case any mishaps occur or you decide to purchase new koi.
Let’s go over how to set up koi carp holding tanks and what significance they hold in the overall health of your koi fish.
Why Have a Holding Tank for Koi?
If your koi are happily swimming in their large pond, you may be wondering why it is necessary to have a separate tank at the ready or near-ready.
While it may sound like a bunch of wasted effort, having a semi-prepared holding tank can save you a lot of headaches in the long run.
Since koi fish are so large, they are often prone to injuries. This can be caused by bumping into each other or the rest of their enclosure.
They also are jumping fish and will sometimes slam into rocks and other fixtures, resulting in injuries or nip at each other’s fins.
Having a tank set up can give you a space to put your injured fish so they have time to recuperate and heal without worrying about a further injury in the communal pond.
This tank will serve as a sort of hospital where you can provide medicines and other treatments to ensure your fish makes a full recovery.
For this same reason, having a tank at the ready is valuable in the event of illness.
Illnesses are, unfortunately, fairly common with koi especially if they are exposed to other fish that are sick or animals with parasites.
If you notice a koi is sick, it is best to remove it from the pond immediately and place it into a holding tank until it is well to give it a chance to heal, receive medicine, and lower the risk of spreading the illness to the rest of your koi carp.
Koi that are newly purchased should also be quarantined.
Even fish from reputable breeders or pet stores should be quarantined just in case there is any bacteria or parasite lurking with them.
This also gives the new fish time to adjust to their new home and develop an immunity to the bacteria in the water before being placed into a situation where stress may lower their immune response.
How to Set Up a Basic Koi Holding Tank
Once you have a large tank ready to start the holding tank process, you should fill it with water from your koi pond that is clean and fresh.
Add a heater and filter and place rocks and other natural materials at the bottom of the tank that are not sharp or potentially harmful to help prevent stress in your fish.
The process is honestly very simple and not unlike setting up a normal tank or pond.
If you are buying new fish, try adding in a koi from your pond to act as a sort of “guinea pig” to ensure no issues will occur with your new koi and established colony.
For injured koi or sick ones, be sure you have access to give them treatments and that your tank has a lid to prevent the koi leaping from the water and stranding themselves.
Also, be sure to check the water parameters often to ensure nothing is amiss.
Since a tank is a smaller area, things can begin to go bad much more quickly so it is important to catch imbalances early.
What Happens if You Do Not Quarantine?
For most koi, nothing will happen if you introduce them to a pond without quarantining them.
They will be perfectly healthy and fine and will generally fit in quite well.
However, some koi that are introduced to the pond will be harboring parasites or bacteria that can then spread rapidly through the population.
If caught early, this can be remedied but will be costly and timely, making for a rough few months until things are back to normal.
Worst case scenario, the koi in your pond are all sickened or killed by the imposing bacteria or parasite, resulting in a mass death or mass pandemic.
This means you may have to completely recycle the pond and start from scratch.
While not common in the slightest, it does happen so it is best to err on the side of caution, especially since Koi Herpes Virus is on the rise.
The new koi can become ill too.
If the water parameters were different at their old home or if there is a bacteria present that was not in their old enclosure, the new koi can become very sick or stressed.
This can result in the koi dying or being harmed internally, especially if the illness is present but not detected in the other koi since they are used to the bacteria in their water.
Even the best breeders sometimes miss a parasite or illness.
It is just a simple human error that can have big consequences so it is best to try and keep your koi quarantined for at least two weeks to ensure they have no illnesses or produce an ill impact on your pond population.
It is better to lose a single koi than the entire bunch.
Supervision is Key
When quarantining a koi for any reason, supervising them is key in making sure their recovery goes well or that they are without any illnesses or parasites.
Watch how they swim and interact with their enclosure and pay close attention to their eating habits.
If something seems off, do not hesitate to contact a veterinarian who is equipped to work with aquatic animals for a consultation or treatment.
Holding Tanks and Koi Quarantine
While not the most fun aspect of koi keeping, quarantine tanks play a vital role in keeping your fish safe and healthy and are overall a massive help to have on hand.
Even a smaller tank is a good fit as long as it allows the koi room to move about and be observed while under quarantine. Good luck!