I found this about your Kribensis:
An alkaline
pH seems to produce predominately male offspring, while an acid pH produces predominately females. Neutral water produces a more balanced sex ratio.
Kribensis are good parents. The female guards the eggs and young while the male defends the territory. They become extremely aggressive at this time and will even attack fish larger than themselves. If you notice that your other fish are restricted to a corner in the tank, that's a good sign that your Kribensis are spawning. It is important to have other fish in the tank for the parents to chase (know as dither fish or target fish), otherwise the Kribs may take out their aggression on each other. Good dither fish are fast swimmers such barbs and tetras. Rosy Barbs make good dither fish since they are usually too fast for the Kribs to catch.
The eggs hatch between 3 to 8 days. The parent may move the fry to different locations by carrying them in their mouths. The fry are free swimming in about 5 to 10 days. Once fry are free swimming, they can be fed powdered flakes and newly hatched
brine shrimp. If the tank is mature, there should be enough organic matter for the fry to eat. The parents also assist in feeding the young by spitting food to the fry. The parents will gather the fry into a school and lead them on excursions around the tank. Sometimes one parent may want to take sole care of the fry and will attack the other parent to keep it away. If this happens you should separate one of them before they kill or injure each other. If possible, do not remove the fry from the tank until the parents are ready to breed again. Removing the fry too early may result in domestic violence if the male is ready for some loving and the female is not.
I hope this helps.
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