Anyone else have tried spawning kois, majority of eggs not hatching, becoming toxic to the water and killing the frys?
I used shredded rope and removed it when the eggs were dropped, place it in a separate tank. However I've noticed that the hatch rate is very low. Any assistance will be appreciated
Congratulations on the spawn. Sometimes low hatch rates can still produce a lot of fry. They are so hard to see in that first couple of days that it is hard to tell how many you have.
After most all of the eggs that are going to hatch have hatched, I usually gently swoosh the ropes around in the water to release any fry left in them, then remove the ropes. I clean up as best I can without harming the fry and change lots of the water. Also, I use Fritz ACCR or a similar product to bind the ammonia that tends to increase after a spawn. I change water and/or use more ammonia binder as necessary. And this is while using a mature filter. If using no filter, flow through, or a new filter, things may be a lot different.