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Thinking about spawning this season

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  • Thinking about spawning this season

    So, I have been tossing aroung the idea of trying to spawn a couple female Dainichi Showas that I have been growing out the past 2 years. One female is yonsai and the other is gosai. I have been doing some research on letting the pairs do it naturally (instead of putting the koi under). I have the space to set up 8ft diameter spawning tanks, but after that, how much more pond space will I need to give this a decent try? I have space on my property for more large grow-out tanks for the fry, but I know I will be at a huge disadvantage without a mud pond or large body of water. I could stretch out a large liner (15 x 40) to create a body of water, but this is not my first choice.

    I read that mortality rates for the fry is highly affected by having adequate space, food and water quality. I am confident in my ability to produce decent water quality, but adequate space and having enough food for thousands of fry will be a hurdle for me. I will need to be culling fry hard and often if I am to learn something here.

    Some questions that I have in the spawning tank:

    1) I noticed on videos that some breeders use a fine netting with pvc frame inside of the spawning tank. Is this to protect the koi or is this to allow all the eggs to be collected without draining the tank?

    2) What is the best water cycling/exchange rate for filtration in the spawning tanks? One-two or three water cycles per hour in the tank? I don't want to just place air stones, am I thinking right?

    3) Once the spawning is completed, and spawning material is covered with fertilized eggs, should the fertilized eggs be removed from the spawning tank and placed into better water quality conditions with Mal. green and heavy airation?

    4) What is a proper depth for a fry grow-out pond/tank? I's like to get a head start to grow out some green water before everything gets going.

    I have many more questions, but these will help me get started with my planning...
  • #2

    The tank used for spawning should be netted to prevent jumping out. Net can line the tank to capture eggs. The eggs stick to surfaces. A spawning rope is often used to capture eggs, and the soft material is thought to assist in inducing spawning.

    Often the prospective parents are placed together at the end of the day and spawn overnight or in the morning hours. If they have not spawned, they will be removed and the attempt made another time. So, no need for any filtration, which could suck up eggs. Airstone is sufficient. They won't be there long.

    Removal of eggs is best. Spawning water will be trashed.

    The big problem is what you've already identified. If you just want to raise up a few with no real goal of getting anything worthwhile, a smaller pond of 700-1,000 gallons is enough. To have any hope of having a few worthwhile offspring, it's all in the numbers. You need the space to raise up a couple of thousand to a size for you to be able to make culling decisions. For amateur beginners, I think you need to be aiming for 2-inch size. Of course, with Showa, you start culling as soon as you are able to see the difference between free-swimming black ones and yellow/white ones. Keep only the black ones. You need to establish greenwater in the grow pond before spawning. No filtration on it until the little ones look like a fish (not a squiggle),and then nothing that could draw the little things into the filter.... wait as long as the water allows. Could be a couple of months. If big enough, no filtration on the grow pond is ever needed, but I doubt you'll have one that large. Filtration will reduce the insect life in the pond. That's bad. Encouraging insect larvae will help feed the little ones. Since you are in Hawaii, I think the grow pond could be just 24-36 inches deep, but be sure it has shade to prevent over-heating and lowered oxygen levels. Your first choice may not be a 9-foot x 35-foot liner pond, but how else are you going to create space for what will hopefully be thousands of fish? You can go smaller, but the smaller you go, the less chance of producing worthy ones.

    Before starting, read up. You can start by reviewing Adam's website. You may not get into it that deep, but lots there to learn from.

    You may decide that for the first time you'll just raise up a few for the experience of doing it. In that case, go with whatever is most easily managed and don't get disappointed if none are worth permanent pond space.


    • #3

      Thanks Mike! As always, you set me straight. I have a lot of prep work to do (right now!) if I am to be ready this season. I surely want to learn if I chose to go down this road, but I also want to see what could come out. One concern I have with the grow out pond will be the mosquitos that will be drawn to this stagnant body of water. Not something the family will be tolerant of. Any tips to minimize this specific criter?

      I can provide temporary tent structures for partial shade for the morning - mid day sun (East side), water body will be in shade in the afternoon. In order to get the green water, wouldn't I need direct sunlight to get the algae going? If I cover the water body (tent), is this okay? I want to keep the dirt and debris out of the liner pond. How about the smell of this stagnant water, with no filtration and generally open to the elements, I'm guessing that this could get unpleasant. I have a decent size property, but still need to keep this under control (if you know what I mean). Now that I am thinking about this, more questions are arising.


      • #4

        The fry ought to keep your mosquito concern to a minimal.

        Spawn the older female as her eggs will be healthier and survival much better.

        Put female in the tank you expect to have spawning activity in, first. then add the male towards evening after she's beenin the tank 3-4 hrs. spawning is usually in the morning hrs. If you can plan your event close to a full moon (within 4 days) that usually helps as well. After spawning you can return the male to a regular tank of combined sexes (your pond). But really need to have another tank set up for female for a day or two so she gets rid of her scent and allows her to recover from spawning. Since your just learning use one male, that way the female will not get beat up as much.

        when you collect your babies on the third day of hatching, take only the very black ones. You'll see some that look grey and yellow. Start off with smaller numbers so level of stocking and therefore needs are minimal. don't try and keep them all. Remember your learning......
        Dick Benbow


        • #5

          DickB has made important points to have in mind.

          Regarding greenwater and shading, there is a balancing act involved. Full sun to get the greenwater is great. It is after the hatchlings are in the pond that oxygen levels become an item to monitor. If water temp gets much above 82F (28C), you need to pay close attention. It is not so much of an issue when the hatchlings are little slivers you can't even see. It becomes an increasingly important issue as they grow and have higher oxygen demands. ...Something more to learn in your climate.


          • #6

            Thank You Dick. I do have another resting place for the female after spawning is completed. I will do my five year old female first like you suggested. She is a Dainichi Kokugyo offspring I got from Kodama Koi. I hope she doesn't get damaged.

            My females are 30"+ so I am hoping that the 8ft show tank will suffice the spawning activity? Is there a preferred level of water to uphold in the show tank? I will have 5 spawning bristles for the tank, is this enough? Do I need to secure the spawning media to the sides of the tank somehow?

            Question: Where can I buy the appropriate fine white mesh material in x-large rolls? I want to line the interior of the tank with a soft mesh to help collect the eggs and also help induce spawning (like Mike mentioned) I'm thinking of building a pvc frame for easier install inside of the 8 feet show tank. Would the pvc frame behind the soft mesh be dangerous for the breeding pair? Any suggestions on best way to set up? I've been searching on Youtube for managable spawning tank setups.

            During summertime, my ponds water temps reaches 80-85 degrees even with the shade covers. So, I guess I will need to cover the fry grow-out pond as well. I'm concerned about the water quality for the fry. What about devising a water ciculation/filter system for the fry that will not suck them up. Maybe a system with a couple screened overflows to keep everyone safe. Will this be bad for maintaining green water for the fry? Can I introduce green water produced in other water barrels? Is this worth the effort?


            • #7

              ??? You only need greenwater until the fry are large enough to eat dry food. At that point the best approach would be to have a continuous flow of fresh water with the overflow designed so the fish cannot get out. Until the fry are big enough to eat dry food, it is very unlikely water quality will be an issue. Thereafter it is OK if the water is no longer green. They grow fast. In a matter of weeks they will be as big as aquarium fish. At 4 weeks you can cull for deformities. It will be a busy 3-4 months. With your warmth, a continuous flow of fresh water and multiple feedings per day, you could have a lot of 10-inch tosai in 4 months.... if you cull to prevent crowding.

              A lot of folks who do some backyard spawning rave about the experience, complain mightily about all the work and expense.... and don't do it a second time. Still, for years they'll tell about the ones they raised up, like grandparents bragging about their grandkids. It's a lot cheaper to go spend big bucks on high-priced koi if the goal is worthy koi, and a whole lot less time and work. But, for the experience, you have to do it yourself. Have fun.


              • #8

                Go for it, Akai-San. You will learn a lot from the process. Be sure to document for us to learn with you.

                Getting the fish to spawn is not too difficult. Moving the eggs to cleaner water with malachite green will improve your hatching rate. The biggest challenge is raising the fry. With your large female, you will need to have as much water as possible to raise the fry. The first few weeks of their lives is crucial. I would highly recommend daphnia as "baby" food for the newly hatched fry. Setup the fry pond with good aeration ahead of time. As soon as the water turns green, introduce the daphnia. They will feast on the algae and multiply very quickly. Time your spawning to coincide with the daphnia population explosion. Then release the newly hatched fry into the fry pond as soon as they are free swimming.

                Good luck and have fun!

                Last edited by Tosai_Sunny; 03-11-2015, 11:09 AM. Reason: typo


                • #9

                  I didn't know that they grow that fast. I will surely cull hard and often. I know that I won't be able to sleep well with all this action taking place. I already don't sleep much, this could really knock me out, hahaha.

                  I have a trip planned in first week of May, so I guess right when I get back I'll look to pair them up. I'll get the growout pond space set up by the end of this month and get the green water going by April 1st. Lots to prep. To keep things less back breaking, I think I'll put together a temporary piping/valve system to drain and fill tanks. I'm glad I included redundant drain hook-ups on my existing system for this very reason. I knew they would eventually come in handy.

                  How long does it take for the daphnia population explosion to occur? I did find a local supplier of daphnia, so I will definitely give it a go. What about Moina? Are they smaller than the Daphnia?

                  I want to also rig a batch of large water bottles to hatch baby brine shrimp feedings daily. I guess seven bottles (one a day) with the rotifers in the growout. How long will the rotifers last with thousands of fry? 2-3 days? Where is the best place to get good brine eggs. I've been looking online at for everything. I can see that this is a really BIG production. Actually getting excited with all this prep work going on in my head.

                  I don't really have any expectations on what comes out, but I would love to see that I could grow-out a bunch of wild and hungry 4-5 inch showa tateshita.


                  • #10

                    Miona is the smallest of the three most popular types of daphnia. The other two are daphnia magna and pulex. I had all three types going when I spawned my sanke a couple of years ago. Daphnia magna is the most prolific and hardy. They are also the largest. Their reproduction is temperature dependent. Here is a good website to learn more about them: Daphnia

                    Newly hatched brineshrimps are also perfect food for the fry. It does take some work to hatch them, but it sounds like you already have it figured out. Along with the daphnia, I did feed them to my fry as well. I bought the eggs from Brineshrimp Direct(Brine Shrimp Direct | Quality Aquarium Fish Food Products | Quality Fresh &amp, Marine Aquarium Fish Food Products). They also carry brineshrimp flakes which is a good transitional food before switching them to pellets.
                    Last edited by Tosai_Sunny; 03-13-2015, 01:10 AM. Reason: typo


                    • #11

                      Here are three of my home-growns from 2012 spawn with their mama in the center. They are not the highest quality sanke but good enough for my pond. This was my last spawn. If I can find a better quality oyagoi, I might join the fun and spawn a pair this year. Reading your post and Adam Byer's blog have given me the itch. :-) I know the chance of us raising something worthy of greatness from our backyard is highly unlikely, but that should not stop us from dreaming about it.

                      Attached Files


                      • #12

                        Nice! I like them all. You must be proud! I know it is really hard to find nice sanke. Thats why I don't have any. I am wondering if it is okay to reuse the baby brine salt water (at least partially) to keep the cycle going. I'm thinking mixing new salt water every time will be a pain. I know, I know, you get what you put in. Might not be a big deal. Just trying think of ways to be more efficient with the time I have. I will order some brine eggs and design some bottles with collecting strainers this weekend.

                        Did you use soft netting inside of your spawning tank? If you did, where do you find for purchase. Not sure what is the appropriate material for the fine mesh.


                        • #13

                          Thanks Akai-san! Yes, you can reuse the salt solution, but I would not recommend using it more than twice because the water will start smell. The easiest method of hatching brineshrimp is using a commercial hatching cone, which is also available at Brineshrimp Direct. Or you can make one yourself from a one-liter soft drink bottle. I did not use either methods because it is too difficult to heat the water with the cone shape. Instead, I used 2 one-gallon jar beverage dispensers. Both are filled with 1/2 gallon of the salt solution and airstone for aeration. The temperature is raised to about 80F by placing both jars in a heated 10-gallon aquarium with about the same level of water as the water in the jars. At the that temperature, the eggs will hatch within 24 hours allowing me to alternate the hatching between the two jars daily.

                          AS for the spawning net, I did not have one but it is a good way to collect the eggs and move them to cleaner environment. Sorry, I don't know where to get it either. Hopefully, Adam B. will jump in and tell us where he got his net.
                          Last edited by Tosai_Sunny; 03-16-2015, 11:45 AM. Reason: clarification


                          • #14

                            Heated tank to hatch the eggs. That is why I see online, they place a lamp on the bottles. Hawaii is quite temperate, so daytime temps are 75-85 regularly. I was thinking that I needed to set up a bottle for each day (7-2 Liter bottles). If I give the eggs 48 hours, should be good. I was thinking of setting up a fixed/in-place brine shrimp station with valves and strainers. Thinking more, it surely will be 10 times easier and faster just to dump the baby brine shrimp straight from the bottle into a strainer. YES! K.I.S.S. I will just build a cool bottle holder; yup that is what I'll do.

                            If anyone has advice on purchasing and setting up a spawning mesh/net inside of the spawning tank, I am very interested in knowing, learning and planning on this feature for my first try at spawning.

                            What about mosquito netting with a pvc frame? Too fine/weak? I surely don't want koi to break themselves and get tangled in anything.




                            • #15

                              I just had a flash of reality last night thinking about this undertaking. I am so into the preparations for this spawning season and fry care, I TOTALLY forgot about what happens next. What will I do will all the koi that come out of the spawning? I have no expectations for getting top quality results from this experience, but I am already thinking that I will not have the proper pond space available for the koi that I want to move on. I have space to set up large 800-1000 gallon tanks (temporary-permanent), but I'm sure the Mrs. will surely question my sanity. I guess I could thin out and re-home a few of my koi, but I still like them all. Plus, taking out 2-3 koi will not really help my future situation either.


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