Which rainbowfish species is it?
Just keep the eggs in the seperate container at about 25 degrees celsius.
Add some plant cuttings or low bubbling oxygen pump, to keep the water ariated.
Depending on the species, the eggs should hatch in 5 tot 22 days at this temperature.
Some add a drop of anti-fungus medicin in there, I personally have never done so.
Not all eggs from a laying will hatch. So let's hope you found 2 good ones.
Do not move the fry when they hatch until they are at least few weeks old. Even the slightest difference in temperature or water composition will kill them off.
The first few days, rainbowfish fry are TINY. You'll need "green water" or disolved plankton pallets. Liquidfry also does the trick rather well. So gather up plant cuttings and put them in the container. The fry will feed of the tiny "stuff" (don't know the term in english) that are always present near plants. Hornwort is ideal for this.
After a couple of days, they'll be able to eat newly hatched artemia or babyfish powder. Always give them ample food. They're not smart enough to go and look for the food. They need to be swimming in it.
Try to keep the water as clean as possible. Since you have to overfeed them, you'll need to remove all the non eaten food as soon as possible. (daily) A few snails will help in eating the extra food. But they'll leave droppings, so you'll need to remove those either way.
Good luck! And keep us posted.
