Many aquarists have found that using a “natural” killifish setup (a tank filled with plants such as Java moss, Watersprite, etc., and several pairs of fish) results in better fry production with less work, but some aquarists have taken the practice a step further.
Here’s a suggestion that a number of breeders have found useful. Go to a craft store and purchase the plastic mesh used for needlepoint. It comes in varying grades of stiffness; the stiffer the better. This plastic “grating” material is inexpensive, easily cut to size, and makes excellent tank dividers and breeder containment structures. Its open weave allows good water flow-through, so all parts of the tank benefit from filtration, and small fry can easily swim through the mesh, while their parents can’t.
If you place the tank with the short end towards the light and the parents in the back, “dark” compartment, the phototrophic fry will go through the mesh toward the light and safety, away from their parents. If the front of the tank is planted, the fry will find sufficient food to sustain them until being removed to different quarters.
Other breeders prefer to put two dividers in the tank, keeping a breeding pair of killifish in the center, planted, section. Fry would then migrate to either end of the tank for later collection.
– G.C.K.A. Newsletter, November 1999