Egg laying fish love to spawn in live plants. One of the common way to mimic these plants is the use of yarn. Be sure to pick a dark colored acrylic yarn as it will not break down in the water over time. I generally pick green since it best mimics actual plants.
Alot of egg scattering tetras and danios tend to eat the eggs after the span which can reduce the number of surviving fry.
Egg scatters tend to have less sticky eggs that will fall out of the mop if you shake it so be sure to have something underneath to catch the eggs if you plan on moving them. With most small fish its a good idea to separate the parents from the eggs once the span is over.
Start by wrapping the yard around a book about 100 times.
Next tie a not on one side of the the book to hold the strands together.
Cut the opposite side of the yarn
Tie another chunk of yarn at the top to create a blub on top and hold it all together.
Next Boil the mop for at 5-10 minuets to leech out any impurities and make it tank safe..
The threads may float for the first 24-48 hours until the threads become water logged.
The mop can either be tied to the top of the tank, or to a cork to let it float around.