Top Dog

[bekko]

I agree with Luke and Maurice. Let the fish do their own thing. If you are going to use hormone injections and strip spawning, then practice a few times on junk fish first so you do not kill your best broodstock. I have never strip-spawned koi, but have done it with some other species. There is a lot of handling involved and it’s hard on the fish. We would tend to lose them 5-10 days after spawning. I suspect this was because the handling stress compromised their immune system and they would succumb to the inevitable bacterial infection.

Put the fry in the mud pond. The first days are the most critical and you want them to have the stable water quality and diverse abundant food of the mud pond. Look up the thread on growing fry in green water which ended about 9-5-2004. There may be others in the archives of this board.

Some like to put the spawning mat in the fry pond and others like to wait and move fry to the pond when they are ready to begin feeding. Personally, I like to put the spawning mats in the pond because the water quality can get pretty rank in a hatching tank from all the hatching debris.

Preparing the pond for stocking is an art in itself. Everyone develops their own technique based on local conditions and what works for them. Here are some steps often used:

• Drain the pond during the winter if you can.
• Dry the bottom if you can.
• Plow the bottom if you can (this works magic and is strongly encouraged).
• If the bottom cannot be completely dried and plowed, then spread some quick lime to oxidize humic organics and kill off some of the bugs.
• Send a soil sample to the local agricultural extension service for a soil analysis. Tell them what you are doing so they will know what to recommend.
• Add agricultural lime at the rate recommended in the soil analysis report.
• Fertilize the pond. Everyone has their preferred method. Some use something like prilled urea which is heavy on the nitrogen. Others use the liquid pond fertilizer while the pond is filling which is heavy on phosphates. Still others use organic fertilizers. I like to add enough of a general balanced agricultural fertilizer to yield about 0.5 to 1.0 ppm of nitrogen when the pond is full and a similar amount of phosphate. Then I also add organic fertilizer at a rate of about 100 to 200 pounds per acre (11 to 22 grams per square meter). The inorganic (chemical) fertilizer gets the phytoplankton (algae, green water) going quickly. The organic fertilizer gives the rotifers, copepods and other zooplankton something for grow on while the algae bloom develops.
• Some like to use the “puddle method” and fill the pond very slowly over several weeks, saying there is better light penetration to get the algae going. I like to fill the pond more quickly to stabilize the temperature.
• Here’s the tricky part. You want to start filling the pond 10 to 30 days before the fry are ready to begin eating. In some areas, you have to stock within 10 days to keep the predacious insects from taking over the pond and eating the fry. In other areas, it takes up to 30 days to get a good “bloom” going. In Georgia, target 15 days and adjust based on the first year’s results.
• Obviously, you cannot predict the exact spawning date so there is some luck involved in getting the timing right. As a rule of thumb, figure your fish will spawn around the time of the full moon after the temperature reaches 68 F (20 C). Cold there this winter, huh? If I had to guess, I would say May 23rd for you, but it might happen at the end of April. February 24th for me (na-ne-na-ne-boo-boo).
• Do not fertilize and fill all the ponds at one time, but stagger them. This increases the odds of having a good pond when the fry are ready to stock. As the time approaches, start monitoring zooplankton. The easy way is to set a flashlight on the edge of the pond at night and wait about 15 minutes. The zooplankton will swarm around the light and give you a quick indication. Alternately, you can pour a liter of water through a small sieve with 30 micron mesh and count the number of food items under a microscope.
• If you can get one rotifer per ml, the fry will love it. Typically, you have to try to get by with less. Ciliates will also work as a first feed but the fry are soon looking for something larger. There is typically a succession pattern. First you will see phytoplankton (green water, single cell algae). Then you will begin seeing ciliates of various types. Then you will start seeing rotifers which are slightly larger. Then you will start seeing copepods which are larger still. I don’t know if its coincidence or nature’s way of taking care of young fish, but larger food items seem to come along just about the time the fish have grown large enough to eat them.
• Some people start providing supplemental feed (out of a bag) immediately. Others wait until the fry have been in the pond several weeks to a month. I just watch the zooplankton numbers and add supplemental feed if the numbers are low. You will want to start with a feed called something like “No. 0 Crumble”, or “fry powder”. Check the feed stores in an area where there are catfish farms or order direct.
• Get some aeration equipment and a dissolved oxygen meter. The combination of spring, fertilizer, green water and feed can depress oxygen in a hurry and young fish are very susceptible. Either run the aeration equipment continuously, or check the oxygen every day at dawn and be prepared to turn it on if the dawn readings start looking low. Tell us the pond size and we can recommend some equipment. Pin Point or YSI brand oxygen meter.

There is a dude named Dr. Gary Burtle at the UG experiment station in Tifton Georgia who can help you at lot. If you can’t get to Tifton, then tell your local agricultural extension agent that you want an Aquaculture Specialist to help you. You will be amazed at what these guys are willing to do for you if you ask them and smile nice.

-steve hopkins

[sundan]

There is very few info on this subject koi spawning. Here are the few sites I have found useful.

http://www.vcnet.com/koi_net/spawn.html

http://www.efreeman.demon.nl/spawning.html

http://homepages.nildram.co.uk/~koi/spawning.htm

[MikeM]

SteveH: Another great post! That & the links from Sundan give quite a knowledge base. I think most magazine articles give too little focus to the importance of cultivating the microbe life for the first food for fry. The first weeks are so important ... and difficult ... with any fry. With hundreds of thousands of fry, the food volume needed is extraordinary, and depends on a careful balance. You also made the the important point of timing re: predators. Once the dragon flies lay eggs, time is short before fry are the meal of nymphs etc. So many things for the koi breeder to do ... all in the right time span. So much work before the "art" even comes into the picture.

[koifishgirl]

Dont dragonflys lay their eggs on plants? What if a net is used at all times to cover the pond?

[koifishgirl]

Hi Steve, The pond is under construction at this time and will be a 60x60x6ft deep to raise the fry. I will be using a drilled well to top the pond off every day and will be filling with city water to start, I plan on putting a large pump in the middle of the pond surrounded by a large very fine mesh net to keep fry form being sucked into pump. Will lime the pond to start out with to kill any bad bacteria and will ferterlize using liquid fert. I will start this process about two weeks before I get ready to release the fry. I will be using a large pool to spawn and hatch my koi and after 4 days will put in mud pond. I plan on keeping the top of the pond covered with a good net to keep out birds and other things like turtles and large animals like deer as we have alot of them. Blue herons are kind of bad around here to so I am going to do what it takes to keep them out.

Sound like you are very knowledgable in this field and I am gald to be corresponding with you. If you think this method will not work with the way I plan on doing the pump I will be open to any ideas and other info that you may have to share.

[dick benbow]

Your pond depth is too deep for nosehair sized fry and I don't believe you'll have any luck with your net/pump concept. keep an eye out for dragon fly larvae

the first time you run your catch nets for your first culling and crush everyone of them!

hats off to sundan and bekko for your helpful posts!


good luck KFG!

[koifishgirl]

I dont understand, why do you think the pond is to deep? I realize that I will have to get in the pond and what makes you think I will crush the fry? If the pump wont work what do I need to do? A large mud pond I would think of this size I can wait a least a month before I do my first cull. What is the best depth for the pond?

[bekko]

You can build the pond 6 feet deep, but do not fill it to that depth for fingerling production - 3 feet should be enough. Being able to dry the pond will make your life much easier. Depending upon the water table, that may be a consideration in deciding the pond depth.

What's your soil like? That nasty red Georgia clay is excellent for pond building, but will probably need to be limed heavily. If you are digging the pond now, then go ahead and send off the soil sample for analysis. The local Soil COnservation Service provides free advice and design work on pond construction.

That pump in the middle of the pond will drive you crazy. You will have to get in the pond to clean the screen and the screen will clog frequently. If you are going to use the pump, then put it on the side of the pond. Make a 2-3 foot diameter x 3-4 foot long cylinder of 4-inch mesh welded wire - the stuff for reinforcing concrete. Cover that with 1/2 inch plastic mesh like this stuff:
http://www.aquaticeco.com/index.cfm/.../iid/3143/cid/
Stick the whole cylinder inside a big bag made of very fine mesh. After a few weeks you can use window screen, but before that you would have to use fine mesh fabric. Stick the end of a length of 1-1/2 or 2 inch pool hose through a hole in the wire at the end of the cylinder. Put the cylinder in the mesh bag and tie it closed around the hose. Attach other end of hose to pump suction. You want to be able to pull the whole thing up on the bank to clean the mesh or change the bag.

Using a pump to aerate is not very efficient in terms of the amount of oxygen transfered per kilowatt-hour of electricity. Paddlewheel aerators are really efficient and can be used with fry, but they do not make one small enough for your pond. These fountain things are probably the second-best option and would be about right for you:
http://www.aquaticeco.com/index.cfm/...l/iid/135/cid/
I have never used one of these fountains with very small fish and think you will have to wait 2 weeks before you turn it on.

Dragon flys are not the only insect to worry about. Actually, in your area the water boatmen, back-swimmers and diving beetles will be a bigger problem during the first month. They are pretty small and it is not usually feasible to screen them out. If you stock within a couple of weeks of filling the pond, the fish will pretty much stay ahead of the dragon fly larvae - but you may lose a few.

Netting the pond is always a good idea. 1-1/2 inch predator netting will keep out dragon flys. More importantly, it will keep out the herons and most bullfrogs. An adult bullfrog will eat fish up to almost 3 inches. You can run plastic wire (see aquatic ecosystems catalog again) across the pond at 4-6 foot intervals and use it to keep the netting from drooping into the water.

-steve hopkins

[MikeM]

DickB was referring to crushing the dragonfly nymphs. I think you would find it useful to pay a visit to a fish farm. There will be lots of mistakes the first couple of years. Might as well skip a few by checking out the operations of an established farm. Even a catfish farm would have lessons to provide.

[koifishgirl]

Hi Steve, What size would you recommend for the fry ponds? I want three ponds. And what about after they outgrow that pond, what size will I need for a finishing pond? I dont plan on keeping over 20 fish. If the 60x60x6 is big enough for them I will keep that the same and make a 3ft deep pond for the fry. And yes it is Ga. red clay that we have here and what I am thinking is a pond 3ft deep will be hard to keep water in. How long would I be able to keep the fry in a 3ft deep pond. I would think it would have to cover a very large area for the fry to grow to any size. Keep in mind that I only have two acrea set aside for this project? I will be using a drilled well to keep pond full and will use city water to fill the first time, so I will have to have some sort of pump to get the colorine out of the water. I dont like chimicals and stay away from them if I can.