Quote:
Originally Posted by
bekko 
You will want to keep fry ponds dry until about two weeks prior to spawning. You fill and fertilize just prior to stocking eggs/fry so that that the rotifer bloom will occur just as the fry are ready for first-feeding. The copepods will bloom up next and be there when the fry are ready for a slightly larger food.
If the pond is filled too early, there will be a lot of predaceous insect larvae and other larger life forms which eat zooplankton and the fry themselves. There are predictable successional stages in the pond biota after filling which you want to take advantage of.
One of the primary advantages of spawning koi using hormone injections and stripping is that you have more control over the timing of the spawn. If the pond zooplankton bloom is ready but the fish are not ready to spawn of their own accord, you may have to drain and refill the pond to start the successional process all over again. Artificial spawning is tricky, dangerous and not for the faint-of-heart. However, the growth rate of the fry can be remarkable when the timing is right.
When you have some time, you might want to do a KoiBito search and read the trials and tribulations of (user name) koifishgirl. It will be entertaining, if not informative.
-stevehopki ns