How To Catch Koi From Ponds
Netting Koi - Backyard Ponds
Easiest method is to drain the pond so only a few inches of water left. If you drain the pond, you can use just about any tight mesh net. You don't really want to use landing nets that you get at the sporting goods store. That type of net has about an inch grid, and the fins & scales of the koi will get caught in the net, tearing them off. You really want to get a net that has a much smaller mesh, like 1/4" holes.
Catching koi in a fully filled pond is a lot trickier than it looks on youtube videos. After years of practice, I finally learned how to do it and can select one koi out of a full pond pretty easily. But to do this, you really need to have a proper koi pond net. They are large in diameter but very shallow in depth. Many people use 24" diameter nets, but personally I use a 42" net. The bigger the net, the easier it is to catch the koi, especially the bigger ones.
And besides, a large bowl net is really useful to every koi owner, so if you need to select out one of your koi to see if it needs medical treatment, or for when you are picking out the koi you are going to take to a show. A word about koi shows -- I know some people around koi shows get super serious, but most shows allow amateurs and showing koi is really fun, even if you don't win anything. You get to be around other koi enthusiasts and have a fun time, and see a lot of really pretty koi.
Picking Up, Holding and Carrying Koi
Koi are large fish that don't have very strong bones, so you gotta be careful. When you net the koi, there is a special technique for lifting and carrying koi by hand. I found this video on youtube, and it does a pretty good job of showing how to handle small koi. For smaller koi, you place one hand under their head, the other hand under their anal vent, with their head pointed towards you. I know it sounds strange, but the problem is that koi will be still and then suddenly do a big jerk and flip their tail. If you aren't holding them properly, they will break free of your hands and end up falling on the ground, possibly breaking their back. Also shown in the video is the technique of sliding a plastic tub underneath them while in the water, then you lift the tub and fish out together.
For larger koi, like in the 24" and bigger size, you will want to tuck the head of the koi closer to your arm pit. The bigger koi will do stronger jerks to try and get free, and you need a better hold on them.
Using Sock Net To Carry Koi
As you can see by the above video, it is kinda tricky to pickup and carry koi by hand. A much better technique is to use a thing called a sock net (this is what koi dealers use). It is basically a short stick, ring on one end, with a fabric tube. You can slide the fabric tube (sock) over the koi and lift them. When you get to the tank to put your koi in, they slide out the other side of the sock. That way the koi slides one way through the sock. If you try and have the koi go back out the way they came, they will catch their fins on the net and be damaged.
And like the bowl net above, every koi owner really wants to have a sock net too for handling their personal koi. It is just so much safer and easier using one of these.
Catching Koi Large Ponds
I have tried just about everything, and the most effective method is to have a group of people drag a seine net across the pond, after it has been drained to leave about 12" of water. The pond owner (like the golf course pond) usually takes care of draining the pond, but if you need to do it, you can rent trash pumps for about $35 per day.
The best seine net we have used is a 7' tall x 100' wide net, but they are kinda expensive. There are less expensive seine nets that are 4' tall and 25' wide, I have use them by attaching the ends of a couple together so I end up with a seine net that is 4' x 75'.
If the pond is not being drained, and you are just trying to catch one or two koi from a pond and/or you are working alone, a cast net is very effective. For more info, see: How To Use Cast Net For Catching Koi
Dividing Up The Koi
What we typically do is everyone brings their transport containers to where we are landing the koi, and just load up the containers next to the pond. While netting more koi, it is easy to change the water in the containers so the koi can have more fresh water.
After all the fish are caught that day, then pick names from a hat to create an order to go in, and each person gets a turn picking one fish they want. If there are still fish available, do another round of picking. Lots of people like to help catch fish and don't want to take any home - which is fine, glad to have all the help we can get.
Koi Transport Containers
If the water isn't too hot, you can transport a large koi for about a half hour in a plastic tub. The hotter the water, the less oxygen it can carry. To make sure you have the longest travel time available, just before you leave the pond, do a water change so it has the most oxygen in it. Better would be to drop an airstone from an airpump down into the water as you travel. Also remember that the more fish you have in a container, the less oxygen they will have and that means less time in the container.
Stock Tank & Trailer
I have handled so many rescue koi, that I decided to get serous about a real transport system. I have a small sailboat and when I need to do a rescue, I slide the boat off and carry a 100 gallon stock tank. I made a plywood lid that has a door so it is easy to lift up, slide in koi and shut the lid. When I am doing the rescue, I run an exension cord to the house so I can keep a bubbler running in the tank. When driving down the road, I have a 12v to 110v converter in the car so I can keep the bubbler running. The nice thing about the oval tank is that the koi will naturally sit perpendicular to the direction of travel, so if I have to slam on the brakes, they won't bonk their noses.
When I get back home, I can unhook the trailer and wheel it to my back yard where I have the quarantine tanks setup to receive the koi. Extra bonus when I am taking my fish to a koi show, I can use this to haul my koi and don't have to bag and box like everyone else does.
How to introduce into your pond
Koi are very sensitive to changes in water temperature and PH. If you change those too quickly, they will go into shock and possibly die. The best way I have found is when you get home, add some of your pond water to the transport container and wait about 10 minutes. Then add some more water, wait, add a little more so the koi get acclimated more gradually.
Also there is a product called "stresscoat" which you can add to the water, it helps calm the koi. It is made from tea tree oil, and does wonders to naturally calm the koi. Infact... when people exhibit their pond in the annual pond tour, I hear that many of them dump lots of stresscoat in their ponds the day before to mellow out their fish for all the visitors the next day.
Koi tend to jump when first introduced into new ponds!!
You need to check on them every 15 minutes for the first few hours you have them. They are frightened by the new surroundings and may jump in an attempt to get back to where they came from. A big help is to put lots of stuff in the pond for them to hide in, and to have lots of things floating on the surface to give them cover. Like if you have inflatable pool mattress, put a few of those on your pond to provide cover they can hide under.
If your koi starts floating on it's side, and stops moving it's gills (or if jumps out and you found it on the ground), you can revive them. Gently move them back and forth in the water to get the water flowing over their gills, and hold them in a water current. If you have a small pump available, then hold their mouth near it to get the water flowing over their gills. I have a small 66 gph pump that I use in their mouth, and have successfully revived fish that appeared dead. Seems to take 30 to 90 minutes to revive a koi.
Are rescue koi healthy?
Some yes, some no. Ironically the koi that came from the scottsdale golf course ponds were examined by a vet at the koi seminar, we did scrapings and gill clippings and both showed that the koi were without parasites and very healthy. The vet said the reason for that is because in a natural pond, mother nature has a balance for everything and there are organisms that feed on the parasites, which attack koi. We also took scrapings and clippings from koi purchased as Walmart - and those fish were covered in parasites. The reason being is that they have a central filter system that supplies all the tanks, so if one fish has parasites, they all get the parasites.
Most koi that come from backyard ponds do seem to be healthy and parastie free, that is because they have usually been isolated from other koi for a long time and if there were problems, either they would have died or the previous owner would have treated and fixed the problems.
All that being said, you really should you quarantine any new fish coming to your system. Every koi pond owner should have a quarantine system (QT) which includes a tank such as a 100+ gallon (or larger) stock tank or play pool, net cover, filter, circulation pump and/or other aeration device. As a koi owner, your koi might run into problems later on and it is good to have. If you rescue koi on a regular basis, you will want to have this secondary system for the koi you adopt out.