Here is a good method for getting killifish eggs with plant spawners and hatching them.

Acrylic Yarn
any book
Pair of breedable killifish

Step 1:

Ok so you probably have tried to get killifish eggs before and then you try to hatch them and it does not work. Well there is an easier method to do it then picking eggs out of the mop.
First make a spawning mop by wrapping the yarn around the book and then cut it after you feel you have wrapped it enough then tie a knot around the yarn by sticking another piece of yarn through the yarn around the book and tie a knot. Then cut the opposite side of the yarn you just tied a knot around.

Step 2:

Take the mop you made and boil it for 10 mins. Use a stove do not microwave it just melts.

Step 3:

Add the mop to your tank of killifish.

Step 4:

Wait for about a week or 2.

Step 5:

Remove the mop from the tank.

Step 6:

Change part of the water from the tank the mop is removed from.

Step 7:

Add the mop to your bucket of dirty tank water.

Step 8:

Add duckweed and Java moss to the bucket.

Step 9:

Wait for the eggs to hatch.

Step 10:

Skim fry off the top of the water by luring them with a flashlight to the surface. Acclimate to a raising tank.

Congratulations you have now successfully spawned plant spawning Killifish.