How do I keep the eggs and babies from eaten?

The most common way to keep eggs from being eaten is to use a separate breeding tank. There the parents can spawn or give birth to their young, and be removed once they are done. Egg scatters can be placed over a piece of netting, a grate, or a bed of marbles to protect the eggs as the fish spawn. Bubblenest breeders and mouthbrooders can be left in the tank until they stop caring for the young. Livebearers can be allowed to give birth in a dense thicket of plants or plastic spawning grass, so the babies can hide until the mother is done giving birth and is removed.

A breeding tank also is good because it can be kept clean. Eggs and fry need very clean water to hatch and grow. There are also no adults around to compete with the babies for food. Many breeders use a bare tank with only a sponge filter as filtration. Debris and extra food are easily seen and siphoned off daily. Frequent water changes can be done on the tank, as there are no other fish around to stress.

Another solution is to allow fish to breed on yarn mops, a plant, or a piece of slate or glass in the community tank. The eggs can then be moved to the breeding tank to grow. This works well for angelfish, catfish, and Australian rainbowfish. Killifish eggs can be collected from peat or yarn mops and set in a separate container or dried to incubate. Livebearers can be bred in a commercial breeding trap or breeding net within a community tank. The trap separates the babies from the mothers and then gives the babies a safe place to grow.

Some cichlids protect their babies well enough to just be left in a community setup, although this can stress the other fish in the tank. In fact, there are species of cichlids that will turn on each other if there are no other fish in the breeding tank for them to threaten.