[ranskye]

i wont reply about the offspring cause i mainly produce feeders, im trying yeah im not finding many show fish among my batches ...but anyway i have bred hundreds of pairs of kois over the years and for me spawning koi is moslty about the water you are spawning them in as long as it is spawning season and they have reasonable eggs.
i have never had to cool or heat the water to induce a spawning response.
what i do is always use brand new water. my water is from a bore and so has little nutrient or ammonia etc compared to the pond the fish are kept in and as such it makes the fish think it has just rained having paired them up in the freshly filled pond.
i will point out that i run my main brood pond fairly dirty, but this seems to help me to have them not spawn untill i want them to. as ive said before i dont even mind some salt in the pond as i believe this also helps me to keep them from spawning, doesnt hurt anyway.
in rain water there are very few salts. so thats just my way of thinking.

i do not need to rely on moon phases either or sunny periods. none of that seems to matter to my koi. i prefer rain for spawning and then sun afterwards but my schedule of breeding doent allow for me to wait for the ideal conditions.
a major trigger for koi would be rain. it is que for many species of fish.
rain often equals new cleaner water and the deal goes that the fish spawn after a rain and leave their eggs around the place in waiting, the rain stops and the water then contains nutrients as the floods waters drop, so a few days after spawning the hatched out fry will have food from the bloom that has occured. this is how i see natural spawnings anyway.
with rain you often get these high and lower pressure systems and temperature changes etc so that might be one way but it doesnt seem to be sure fire enough for me, i find new water does it everytime regardless of anything else.
so i keep my fish seperate in their sexes, in cages or net pens i have all my females and in another cage pen within the same pond ill have all my males.
come spring to summer time they have plenty of eggs, often in different stages of maturity. but i pick out females i like the colours of and that are fat. ive found even the ones with half bellies still spawn, ill use them if i desire those colours in my fingerlings quickly it just means less eggs.
out of twenty fish i may find one that hasnt spawned which i throw back in the pen of "yet to be spawned fish" to breed next time round.
this allows me to know which ones to pick next time and not to stress out then ones that i am resting, so that they may roe up again.
when i choose males there is no real need for checking for milt as they will all no doubt have it happening at that time of year if they are healthy, just it may be that it is not running so much. but within a day in the new water next to the female that is beggining to ovulate he starts to run in his milt production. he may do it because of the new water but alos he gets turned on by the presence of a female.
not many of my males will have rough operculum /gill plates until they go in the new water some do and they are often running better in the milt department. this may happen if they find theyre pond water gets a good percentage of rain water during rains but they are kept a few metres from the female pen so nothing spawns and rain by itself never means a major change of water quality in such a big brood pond..i often top my brood pond up with recycled effluent pond water.

if however i dropped nearly all the water and changed it with bore water i am sure within a few days they near would all spawn. i find this can happen regardless of presence of males.
as such i believe that the female is the major one that decides and gives indication to the male that she is ready to go. she ovulates and he pushes her around. the males seem to know which ones to push anyway.
the thign koi fish girl mentions is correct, most of the males after spawing will be rough on the gills and sometimes on the pecs but as i say i think it is the female firstly that decides she is ready- or should i say is the egg decider when the triggers are present. i find males to step up to the challenge even if they arent rough before hand. so if you have a rough gilled male he still needs a ripe female and the triggers to force the female to get her chemicals flowing.


this year i decided to breed a few pairs of gin rin in one new pond as they seem to get predated upon when i mix them with other types when breeding.

i put the females in a spawning cage in a new pond and left the males in a cage in their home pond and intended on pairing them up in the new pond the next afternoon.
i did this as i wanted my bore water to settle out some more iron.
it was still a bit rusty and i didnt want the rust to settle on the eggs or matts but i figured i would get them pairs ready as i had time and the net pen was dragged up ready to choose from as i was selling some of the uglier breeders off also that day.

now i thought that maybe i would lose one females eggs as i have seen females just go on their own before in new water but instead of dragging the net pen up two days in a row i took the risk, problem was these fish where in the middle of their breeding season and apparently all primed up ready and as a result i lost nearly every egg from about 6 females that first night.
no males in sight in that new pond! just half a dozen females all spitting eggs on their own.

i new it was possible but didnt think it 100 percent risk. now ive changed my mind with the experience.
i think this goes to show the power of new water and how ready the fish are to begin with in regards to their spawning season.

i have from august through to late february to breed my koi if i can keep them with eggs this long but as time goes on they seem to jump at the chance to release and the triggers could be brought on just by putting the males with the females in the main holding pond.
this has happened in some fish that i was holding together for sale in the main brood holding pond but the others that were seperated did not spawn.
in this we can suggest that the male certainly has something do do with it also as the other females that were seperated from males by a few metres did not release eggs. there was no rain, my water was still fairly dirty but it was cloudy and the females where ripe enough and stuck in a cage with males.

for you, you could hook up a hose to your roof down pipe when it rains and fill up a spawning tank and i reckon that fish will spawn as long as it isnt the case like steve said- some fish just have bloated bellies.

i think that it is possible that the first pair you tried were either not ready or the water or other triggers werent enough.
i dont know whether your water was fresh and new or full of nutrient but it may be the case that after a few days that the nutrient was taken in by a bloom in your spawning tank and as a result the next pair thought that the water was new like rain.
i think we would all agree that there are many things that can be a trigger for succesful spawning but for me its about keeping them ripe, among females only in poorer water quality and then pairing them in new rain like water.