For kribensis, the group question has a short answer: one pair. This West African dwarf cichlid forms devoted couples that pick a cave, remodel the sand around it, and defend the whole arrangement with complete conviction. A male and female together give you the species at its best, her belly flushing deep red as breeding approaches, both parents later shepherding a cloud of fry around the tank. Add a second female or another male, though, and the same devotion turns into persecution, because the pair treats every extra krib as a threat to the nest.
How a Kribensis Pair Forms and Settles
You can buy a ready-bonded pair, or grow a small group of youngsters and remove the others once two fish pair off and start occupying a cave together. Signs of a true pair are unmistakable: they stay near each other, colour intensifies on both fish, and the female begins displaying to the male with a curved body and quivering fins beside her chosen cave. Give them a coconut shell, small flowerpot, or cave at one end of the tank with sand they can excavate. Once eggs are laid inside, the female stays in the cave while the male patrols, and tankmates learn quickly to keep their distance.
Why Extra Adults Cause the Trouble
Kribensis are not vicious fish, but breeding rewires their tolerance completely. A pair with eggs or fry will chase any fish that crosses an invisible line, and another kribensis reads as the most serious possible intruder, a rival that knows exactly what the cave holds. In an ordinary-length tank there is no far enough corner, so the spare fish lives stressed behind the filter, fins nipped, afraid to feed. Two pairs can share only a long tank with caves at opposite ends, visual barriers between, and even then the arrangement needs watching at every spawning. For almost every keeper, one pair plus peaceful midwater fish is the stocking that works.
Tankmates That Live Above the Pair
Dither fish actually help a krib pair settle. Small tetras or rasboras schooling in the upper water signal that no predators are around, and their presence gives the male something harmless to posture at, which strengthens the pair bond. Choose midwater fish quick enough to dodge a warning lunge and large enough not to be eaten. Bottom dwellers are the risky companions, since other cave users and slow substrate fish blunder into the defended zone constantly. When fry appear, the parents guard them fiercely for several weeks, marching the school around the tank in one of the great sights of the hobby, before gradually losing interest as the young disperse.
Living With a Breeding Pair Long Term
Decide what happens to the fry before the first spawn, because a good pair produces batch after batch. Young kribs are usually easy to pass on once grown, but they need somewhere to go, and parents may fight briefly if a spawn fails or fry vanish suddenly, which is normal and settles. Keep the pair's water clean and their cave undisturbed, feed a varied diet with some sinking food reaching the bottom, and resist adding bottom fish to fill the empty-looking space. That space is the pair's territory, and in their accounting the tank is already fully stocked.
A pair this territorial rewards a household that is all working from the same notes, and KinsLe Family Sharing keeps the kribensis pair's cave location, spawning history, and fry plans in one shared profile everyone can check.