How to stimulate sspawn

[SimonW]

Hello friends:

I have got everything ready for this year´s fry, but strangely the koi will not spawn. I wonder what I can do to make them spawn.

I have learned that some condition(s) must change, like a rain storm or that alike. I am thinking doing a PP-treatment to clean out whatever factor that is inhibiting spawn.

[spkennyva]

Are they isolated in a spawning tank? If so, a slight change in water conditions may help. So if they are in a spawning tank, try trickling in some fresh water (chlorine or equivalents may be an issue, so take necessary measures). I've never heard of doing PP to help induce spawning, so perhaps someone else can weigh in on that.

My experience suggests that either they are ready or they are not, and not much can sway them from their natural tendencies. Some years they spawn immediately (within 24 hours), and other times I simply cannot get them to spawn. Most times, mature koi will spawn given favorable conditions.

Good luck, and please share your experiences.

[Matt24]

Are they isolated in a spawning tank? If so, a slight change in water conditions may help. So if they are in a spawning tank, try trickling in some fresh water (chlorine or equivalents may be an issue, so take necessary measures). I've never heard of doing PP to help induce spawning, so perhaps someone else can weigh in on that.

My experience suggests that either they are ready or they are not, and not much can sway them from their natural tendencies. Some years they spawn immediately (within 24 hours), and other times I simply cannot get them to spawn. Most times, mature koi will spawn given favorable conditions.

Good luck, and please share your experiences.

I agree with everything Sean said. The only exception is the 24 hours, and even that is probably due to when I catch my koi. Since my main pond is so big, I can't catch them until it gets dark. So when I move them, I guess then don't settle down enough to spawn by the next morning. But probably a little over half the time, they spawn the second morning. So for me 36 hours is often the case.

Also, I've had times when they would not spawn when the female or maybe the spawning group were not acting like they felt well (not being very active or eating much). Weather fronts can produce temperature and pressure changes that seem to activate them, especially if it rains. I am not sure if sprinkling in a water change can fool them, but I've heard it suggested. Sometimes just moving them to a new location, such as from a pond to a tub can set them off, even if you pump over the same water to the new container. I think lots of water flow from a strong pump plunging into a spawning tub can sometimes spark something. Then there is some stuff that you probably already do, such as putting in plenty of good spawning media that they like and making sure you have no misidentification (at least one male and one female). Water temperature is key. 68-75 F (20-24 C) seems ideal, but I've had them spawn in the low 60's a couple of times.

Hope they get going soon.

[SimonW]

Also, I've had times when they would not spawn when the female or maybe the spawning group were not acting like they felt well (not being very active or eating much).

It is exactly so this time.

I did as I had always done during the last 3 years. There has always been spawning, even in spring/summer 2020 when I got a parasite outbreak. The water is fine (zero ammonia & nitrite, 10 ppm nitrate, pH 8.5, KH 100 ppm).

I treated the pond with PP yesterday, and today it seems that there is some spawning activities. Hope that it works!

[SimonW]

One possibility is that the females already laid eggs when they were still in the over-wintering tank.

I wonder how long time it takes for them to have mature eggs again? If it is once a year then I have already missed this season.

[Matt24]

One possibility is that the females already laid eggs when they were still in the over-wintering tank.

I wonder how long time it takes for them to have mature eggs again? If it is once a year then I have already missed this season.

Most eggy females will be fat in front of the vent. But they will seem slim like a male if they have recently laid their eggs.

I think they can lay eggs a couple of times a year, but I’m not sure.

[Orlando]

I've used the same pair on back to back months and the second spawn was considerably smaller.

[SimonW]

I finally got them to spawn. No egg yet but they are trying!

What I have done:

I added Na2CO3. Since Na2CO3 is more alkaline than NaHCO3 and will give a pH-value of 11.5 I closely monitored the pH-value with drop test kit. pH has been stable during this process, I could not see that pH increased. I stopped after addition of 3X70 grams of Na2CO3, and the volume is 10 m3 water.

I know that I am quite daring :-) Therefore I don´t recommend anyone to try this!

[SimonW]

I got eggs. Unfortunately it was a flock spawn, but better than nothing. Maybe I will get a new variety!

[Matt24]

I got eggs. Unfortunately it was a flock spawn, but better than nothing. Maybe I will get a new variety!

Sometimes something pretty unusual can come out of a big group spawn. Maybe you'll get something you like.