| Don't bother trying to remove the bad eggs. You will dislodge as many good ones as bad ones. Tomorrow you will have a lot of fungus growing on the eggs. The fungus mainly attacks infertile or dead eggs, but will get on good eggs as well. Some of the good eggs will hatch even though they are covered in fungus hairs. Some people use methylene blue to battle the fungus. I don't do anything except try to keep the water clean until they hatch.
Brine shrimp from different sources have different optimal hatching salinity. First, check the container for instruction. If it says nothing, then use 25 grams per liter = 25 parts per thousand = 2.5 percent. Remember, they also need light to hatch.
If you have any green water then give some to the koi fry beginning the day before they are ready to start feeding. All the little protozoans and other bugs in green water get the fry off to a good start. They also ingest algae and detritus from the green water which is good for them. Green water will also increase the nutritional value of the brine shrimp. Brine shrimp are fairly nutritious just after they hatch and before they use up their own yolk reserves. However, after the brine shrimp have used up their yolk and are ready to feed they have little nutritional value and are mostly chitin. Their nutritional value goes way up again when they are feeding on green water or one of the special brine enrichment products. Koi fry fed brine shrimp alone often do not do very well - but it depends a lot on the quality of the brine shrimp.
Some people make a big deal about minimizing the amount of brine shrimp cycts (egg) going into the koi fry tank. True, if koi fry eat brine shrimp cysts it can clog their gut and kill them. However, the koi fry will only eat brine shrimp cysts as a last resort when there is nothing else to eat. If you keep plenty of live brine shrimp and other suitable feeds in the fry tank then you do not need to worry about them eating cysts.
-ste ve ho |