Depends on where they are going and how long the trip is. Preparing koi to be shipped is a little different then preparing to drive across town, although not much. Keep in mind the number one killer of koi is stress. It weakens their immune system and bacteria and parasites simply take over. So when transporting koi it is important to make it as stress free as possible.

Assume worst case.... a large koi to be shipped...this is not easy. First they should be removed from the pond several days if not a week ahead of time. This will give them time to recover from the stress of being netted, also gives you a chance to make sure there are no health issues before transporting them. Even the smallest problem can turn into a major health issue after the stress of shipping. They should not be fed for several days before shipping.

Netting them is a trick in and of itself, especially in a large pond. A good net and a seign may be needed. I also prefer to use a Koi Sock Net when removing koi. Its usually a lot easier and less likely to harm them. Really big koi 24" and above should not be lifted out of the water. They should be netted and then put in a plastic shipping bag in the pond, then removed and released into the QT. Improperly lifting large koi out of the water can cause damage to their spine.

Once they have had a chance to relax and assuming no health issues arose, then you can prepare them for transport.

Large plastic shipping bags can be purchased at several places. Aquatic Eco has them. You will also need compressed air. You can get a small tank and regulator at any welding supply. Harbor freight has a good little O2 regulator for about $30 and the hose and air gun you can get at Home Depot for about $10. Double bag ALWAYS!!!. Fill the bag with pond water and place into a large bowl or container to keep it upright. Roll the top down so it will stay open. Net the koi into a koi sock and gently release into the bag. May require two people with larger koi. With smaller koi you can put them in a bowl and then insert the bag into the water and scoop them into the bag. Once in the bag add just enough water to cover their dorsal fin. If it's going to be more then a few hours you should add a small amount of an ammonia binder. An easy product is called "Bag Buddies" by Jungle lab. Just small tablets you drop in. Then bunch up the top and fill with your pure O2 until the bag is filled (about 1/3 water and 2/3 air). If you are shipping via airfreight, don't fill the bag too full as the air pressure on the plane can cause the bag to burst. Twist and close with a rubber band. Then rebag, but no additional O2, just tie off with a rubber band. Then you are ready to go. You can put the koi into a heavy-duty (double wall) cardboard box and ship it next day air or via air cargo on an airplane (only dealers can do this). If done properly koi can be in that bag for over 24 hours.

The above routine is pretty much the same even if the trip is only a few hours. With big koi you should do the above no matter what. Smaller koi you won't need to QT for a week unless they are on their way to a koi show. You can also just use a large cooler with an air stone if the trip is short enough. There are also heavy-duty koi transport tanks that work well in the back of a truck bed.

To release the koi into the new water, a new QT should be set up. There you koi can have a chance to rest and rebuild its slime coat (which is lost from the stress of transport) before being put into the new pond. Two weeks is a bare minimum for the koi to be in QT. Longer if KHV is a concern. Some people will QT for several months before putting the koi into the main pond. If you just dump your koi right into the pond, its like playing Russian roulette with not only the new koi's life, but also your entire collection.

To release the koi into the QT, float the bag for apx 30 min so the temps can adjust. Then put the koi and the bag water into a separate bowl and gently lift the koi out of the bowl and release into the water. DO NOT MIX ANY BAG WATER INTO THE QT OR VICE VERSA. Some people will add QT water into the bag. This is the worst thing you can do!!! In the bag there is a high amount of ammonia and a very low pH. This is good because ammonia is not toxic at a low pH. But by introducing high pH water into the bag the ammonia INSTANTLY becomes toxic. So never mix any water at all. No bag water should get into the QT and no QT water should get into the bag.