In my community tank full of fish, there is not much chance of eggs surviving, but some species do. In this same tank I have 12 Emperor and Rainbow Emperor fry that are now about 1 inch in length that hatched in this same tank. I removed the parent fish some months ago and gave them away (males were causing havoc, as I've written about elsewhere). The fry started appearing and now they are basically mature and there are 12 or perhaps a few more. But Emperors are prolific spawners, and very hardy fish.
I have two Coral Red Pencilfish
fry in the 33g, now about half an inch. The 7 adults spawn regularly, but so far these are the only fry I've seen. The adults completely ignore them now, so they are safe.
I've had fry from several other characins over the years. I let nature takes its course. In heavily planted tanks it is possible for a few eggs to survive, hatch, and then the fry can get plenty of plankton to eat among the thick plants.
I made an effort to raise the fry from my first spawnings of the Farlowella vittata
a year ago, and three made it and are now in the 33g. I posted photos of the spawning and fry at various stages of growth at the time, if you want to dig out the thread (in the Freshwater and Tropical Fish section). The difficulty with these was feeding the fry; they must have fresh green algae. I tried spinach and zuchini, but I don't think they touched these. But these three found enough algae.