Whenever you introduce a new koi into an existing koi community, it's a good idea to put it into quarantine, to make sure that it doesn't bring any diseases or parasites with it.
This is a case of better safe than sorry – one infected koi can wipe out your whole pond – so a one-to-two month quarantine is well worth the effort.
If you can't create the right quarantine environment, though, then it's better not to attempt it. It'll be more dangerous to put new koi into a cramped or unhealthy quarantine tank than to put them straight into the pond.
So, first things first: get a good sized tank for your quarantine tank. Koi need space to move around, as stress really affects their immune system. 1000 gallons is a good size.
You'll need to use the same precautions that you do with your pond water – it needs to be filtered and oxygenated – and as filters take a while to settle in (it can take a couple of months for the bacteria in the biological filter to grow), this means that you need to set up your tank plenty of time in advance.
It can be a big help to have your tank in a dark place, or to cover it, to reduce the amount of stress the koi will feel from the new environment.
When the koi arrive, they'll be in transportation bags. Float the bag in the quarantine tank for at least half an hour to give the water time to adjust to the tank's temperature – sudden changes of temperature are very bad for your koi's health. Then take the koi out of the bag and put it in the tank, being careful not to get any of the bag water in the tank.
Don't try and give your koi any chemical treatments at first. They need time to de-stress. You can if you like use salt in the water, which is a good general remedy (see koi diseases for more information).
Watch them over the next few days and look for any signs of illness – swimming sluggishly, flashing (showing their bellies), or scratching against the sides of the tank can all be signs of disease or parasites. The sooner you spot any problems in individual koi, the sooner you can treat them (see koi treatment).
This is just an overview, and it's a good idea to read as much as you can about koi quarantine before you try it. Here are some good links for more info on koi quarantine:
- Quarantining your koi at koicarp.org.uk
- Quarantine at koicymru.co.uk
