I once found a TINY fry on the sisde of a 20 gallon tank, I mean it was barely visible. I sucked it with a finger over the end of a straw, it was too small to net. I put it in a planted 2 gallon tank, and it ate whatever micro-ctitters it found among the plants. After a couple months, I finally realized it was a zebra danio. Use a small, heavily planted tank with a sponge filter, and several fish. They scatter the eggs, which are very small. Remove the adults after they spawn.