Backyard Aquaponics
A place to discuss aquaponics

Mate of mine setup a pond ages ago and threw 3 koi in it. it got neglected and 1/2 filled up with rotting leaves and he never fed them.
the koi didn't die, they loved it. there's 40 - 50 3 inch babies in there.

i guess my question is if i want my koi to breed, do i need to let a bit of scum build up in my pond? my goldfish are breeding but not the koi.

are you certain they are not breading? Goldfish could be eating the babies or the eggs if they are breeding. I expect there are ways to improve the breeding of the koi. I've seen special hides for koi as well as breeding brushes or baskets.

well i've got a bit of pond scum at the bottom and a 3 large pots with water iris's in them, i would have thought that'd do the trick.
maybe my koi are still too small

Breeding koi and goldfish is easy. Just put a sexual mature pair/s together and shazam. Also, koi and goldfish will hybridize. I have heard the goldfish industry often induces triploidy (sterilizes them) so folks won't breed them. That could be the problem. The koi need to be larger/older than goldfish to reach sexual maturity. I like my koi to be at least a pound in size.The bigger the better. I have had smaller spawn. Substrate seems to help in a tank. On one occasion they spawned all over the tank. The eggs are sorta clear individual eggs that are adhesive. Will stick to anything.

Koi breed prolificly, but from what I've read most are culled because the brightest colorations are relatively rare.

tamo yea thats the trick. Have you ever seen those fancy types. Check this out.
http://www.nishikigoi.co.uk/index.php?p ... &Itemid=40

That takes breeding.

Such pretty fish.

Pity we can't have them in Vic.

once the koi are feed well ,sexually mature and have enough room they will spawn. and good idea is to use a 'breeding mop'.

we could only manage to catch 2, they have a silver body and metallic yellow fins/head.
the others are metallic black and white.

Koi are quite easy to breed but what most people with ponds find is that the pretty ones are eaten by birds! Also just like goldys many will not express their adult colours until a certain age/size... so be careful the trait you cull for has had time to come thru lol.
You also need a lot of live food to raise the max amount of fry and hiding holes to keep them out of mum and dads reach. Culling fry is a whole nother story though!
Koi will usually spawn big time in spring but they can be triggered a few different ways. There are lots of types of eggmops.
Hard to explain but I use a floating 'fry saver' that I have lots of either cocnut fibre or 'wool strands' coming off it. Once the fish have spawned I turn it inside out so all of the eggs are now protected inside it and let them hatch unmolested this way.
If you have several ponds you can seperate out the males from females (easier with goldfish to sex them but you get an eye for koi after a while) and then control the spawn timing much better.
Another method is to setup a greenwater bloom in another pond (using water from the breeding one) and move the eggs into it to hatch out. Koi are really not that hard to breed but to get max fry survival you do need to take a few extra steps!

that explains why his scum filled pond worked, it's full of leaves and stuff for them to hide in.

http://www.aquaticeco.com/subcategories ... -Incubator

you have no idea how long it took to find a picture of a reversable fry saver.
Ok so I make these for about $3 each in about 20 minutes. Now you have an idea of what they look like you should be able to as well.
Basically fish lay eggs on outside, you turn inside out and leave floating in breeding pond. Just means you can now target feed fry and they are safe from mum and dad.

Cool thanks for that, hadn't thaught of something like this, was more onto incubators and the best is that they could used for lots of fish even exotics.

What do you use for the fuzzy (fake fur) stuff on the outside? Linda

Depends what you have on hand. I have used nylon wool (that I boil before reusing) or in most cases just coconut fibre.
But really theres lots of stuff you can use, even real plants lol.
The number one rule is that it has to be something the fish in question want to lay eggs on and it always pays to make it the best example in the pond!

I have raised a lot of species using different types of floating fry savers. I can also build incubators but find the floating fry savers are such a great way to save space and simplify maintence.