By Priya Ramesh
The cichlid to start with — not the one that scares you off
If you've been keeping tetras and guppies and you've started eyeing the cichlid tanks wondering whether you're "ready," this page is for you. Most cichlid guides online do one of two things: they either make every cichlid sound like a tank-wrecking monster, or they gloss over the real behaviour entirely and you find out the hard way. The kribensis sits in neither camp — it's the cichlid that proves the family isn't all aggression and soft-water fragility.
I'm Priya, the dwarf-cichlid and discus keeper here at Tropical Fish Co. I've bred West African and South American dwarf cichlids for years, and the kribensis cichlid is the one I recommend more than any other to someone keeping their first cichlid. It's not library research — it's what I'd actually say across the counter when a nervous tetra-keeper asks, "could I keep a cichlid?"
This page is the answer to exactly that question. The honest reply is yes — and a krib is where you should start. It's hardy, it's peaceful in a community, it shrugs off the harder tap water that defeats a German blue ram, and it will breed in your living room and raise its own babies. Get a pair settled with a cave and some calm tank mates, and Pelvicachromis pulcher gives you everything fascinating about cichlids with almost none of the difficulty.
Pelvicachromis pulcher — the silver-pink body, gold fin edging and rounded female belly are textbook kribensis. This is one of our in-stock kribs, photographed in our facility. Credit: Tropical Fish Co.
The kribensis is the genuinely beginner-friendly cichlid: hardy, peaceful in a community, tolerant of soft-to-moderately-hard water, and an easy cave-spawner that raises its own fry. The only behaviour to plan around is a temporary, localised territorial streak when a pair breeds — and in an 80 L+ tank with caves and calm tank mates, that's a feature, not a problem.
Fun facts — the stuff most UK guides never mention
The krib is far more interesting than its "good beginner fish" label suggests. Five things worth knowing before you buy:
- The female is the show-off, not the male. In kribensis the female flushes an intense cherry-purple to magenta belly to court the male — the reverse of most fish, where the male wears the bright colours [3]. Practical Fishkeeping calls them "cherry bellies" for exactly this reason [4]. A glowing pink krib at the front of the tank is almost always a female telling a male she's ready to spawn.
- The water pH literally decides whether you get sons or daughters. A peer-reviewed study found that the pH kribensis eggs and fry develop in skews the sex ratio of the brood — softer, more acidic water produces more females, harder water more males — and it even shifts which of two male mating morphs the fish becomes [2]. That's genuine environmental sex determination in a fish you can buy for a few pounds.
- "Kribensis" isn't really one fish. The name is used loosely across the whole Pelvicachromis genus — there are several species traded as kribs — with P. pulcher being the standard, classic krib [4]. The "rainbow krib" sold in most UK shops is P. pulcher; its relatives like P. taeniatus are sister species under the same umbrella name.
- Both parents raise the babies together. Kribensis are monogamous and biparental: after the female lays inside a cave and the male fertilises the eggs, both fish guard the cave and then herd the free-swimming fry around the tank as a team [3]. It's one of the most accessible displays of real parental care in the freshwater hobby.
- Parental personality predicts breeding success. The same research line found that bolder males and more attentive females raise bigger, more successful broods — the fish's individual temperament measurably affects how many fry survive [2]. Your kribs have personalities, and those personalities matter.
If you breed kribensis and always end up with all-male or all-female broods, it isn't bad luck — it's your water. Because pH during the first weeks after hatching biases the sex ratio [2], raising fry in slightly harder water tends to give more males and softer, more acidic water more females. It's a rare case where a hobbyist can nudge the outcome of a spawn just by choosing the water the eggs develop in.
Which dwarf cichlid is right for me? Kribensis vs ram vs apistogramma
The kribensis is usually compared against the other popular dwarf cichlids — the German blue ram, the apistogramma species, and South American relatives. Here's the honest side-by-side, because they are not interchangeable on difficulty:
| Attribute | Kribensis | German blue ram | Apistogramma | Bolivian ram |
|---|---|---|---|---|
| Species | Pelvicachromis pulcher | Mikrogeophagus ramirezi | Apistogramma spp. | Mikrogeophagus altispinosus |
| Origin | West Africa | South America (Venezuela) | South America (Amazon) | South America (Bolivia) |
| Adult size | 8–10 cm | 5–7 cm | 5–8 cm | 7–8 cm |
| Temperature | 24–27 °C | 27–30 °C (warm) | 26–29 °C (warm) | 23–28 °C |
| Water | Soft to moderately hard | Soft, acidic only | Soft, acidic | Fairly tolerant |
| Hardiness | Very hardy | Sensitive | Sensitive | Hardy |
| Beginner-friendly | Yes — the best first cichlid | No | Not really | Closest to "yes" |
| Breeding | Very easy (cave) | Moderate | Tricky | Moderate |
The honest read: if you want your first cichlid, the kribensis wins on almost every count — hardiness, water tolerance, and ease of breeding. The ram and apistogramma are more beautiful to some eyes but far less forgiving, especially in the harder tap water most UK keepers have. Start with a krib, move to the soft-water jewels once you've got cichlid experience under your belt.
The most common reason people avoid kribensis is a blanket belief that cichlids are tank-wreckers. It's simply not true of this fish. Outside breeding, kribensis are recommended community cichlids [3]; the only territorial behaviour is a pair defending the immediate area around their cave during a spawn [4]. Don't let angelfish or Central American horror stories put you off — a krib is a different animal.
Water, tank size and the all-important cave
Three things keep kribensis happy, and none of them are demanding:
1. Forgiving water. pH 5.5–7.5 and hardness around 5–15 dGH suits them, with a real tolerance as wide as pH 5.0–7.5 [3]. This is the krib's superpower — it copes with harder UK tap water that would slowly kill a ram. Steady warm temperature of 24–27 °C, a reliable heater, and clean water from regular changes cover the basics [1].
2. Floor space over height. Kribensis are bottom-dwellers, so what matters is footprint and cover, not open swimming room. A single pair is comfortable in 80 L — Seriously Fish gives a 60 × 30 cm footprint as enough for a pair [3]. Want kribs plus a tetra school and a clean-up crew? Think 80–100 L so everyone has space.
3. A cave — this is non-negotiable for a pair. Kribensis spawn inside caves, so they need them: a coconut shell with a doorway cut in, a small terracotta flowerpot laid on its side, or a rock crevice [6]. Even non-breeding kribs feel more secure with a cave to call home. Add well-rooted plants (Anubias and Java fern on wood survive a krib's tidying), some driftwood and a little leaf litter, and you've built the ideal scape.
Most of southern England runs hard, alkaline tap water — Thames Water classes the London area as hard to very hard [5]. For a soft-water cichlid like a ram or discus, that means RO water and remineralising. For a kribensis, it just means filling the tank. Kribs sit happily in moderately hard water, which makes them the sensible cichlid for the majority of UK keepers who'd rather not run reverse osmosis. If you're in a soft-water area (much of Scotland, Wales, the South West), you're equally fine — kribs span the range. Our water chemistry care guide explains how to check your own supply.
For the wider cichlid-keeping fundamentals — filtration, maturing a tank, water-change rhythm — see our cichlid care guide, and browse the full range on the African cichlids hub.
Tank mates — leave the floor to the krib, fill the rest
Kribensis are peaceful community cichlids, and the trick to a harmonious tank is simple: give the krib the bottom and let everything else use the water above it [3]. Mid-water schoolers are the perfect companions — they animate the top two-thirds of the tank the krib largely ignores, and they're never in competition for the same patch of substrate. The only friction point is breeding time, when a pair defends the immediate area around its cave, so you want tank mates with somewhere else to be [4].
Kribensis tank mate compatibility
| Tank mate | Verdict | Why |
|---|---|---|
| Neon & cardinal tetras | ✅ Good | Mid-water schoolers |
| Ember tetras | ✅ Good | Tiny, peaceful, top of tank |
| Harlequin rasboras | ✅ Good | Calm mid-water |
| Neon tetra schools | ✅ Good | Classic krib companion |
| Corydoras | ✅ Good | Share the floor if space allows |
| Cherry & peaceful barbs | ✅ Good | Active but not aggressive |
| Angelfish | ⚠️ Risky | Fine in a big tank — both want territory |
| Honey & dwarf gouramis | ⚠️ Risky | Calm surface fish; watch a breeding krib |
| Bristlenose pleco | ⚠️ Risky | OK with space — both bottom-dwellers |
| Other territorial bottom cichlids | ❌ Avoid | Compete for the same substrate |
| Large / aggressive cichlids | ❌ Avoid | Will bully a peaceful krib |
| Fin-nipping tiger barbs | ❌ Avoid | Harass and stress kribs |
| Very tiny fish (when breeding) | ❌ Avoid | A guarding pair may chase them |
The reason mid-water tetras and rasboras work so well is the vertical division of labour: as the Fishtory care guide notes, kribs are floor fish that patrol and defend the bottom, so peaceful schoolers up top complete the picture without ever crossing the krib [6]. For a broader shortlist of small, peaceful species that pair well, browse our community tank fish hub. And if you're weighing a krib against an angelfish as your centrepiece cichlid, our angelfish UK guide compares the two properly — the angelfish is the bigger, more territorial South American option.
The rainbow krib in profile — note the dark lateral line, the gold-edged fins and the ocelli (eye-spots) on the dorsal and tail. These markings, plus a glowing belly in breeding females, are how you read a healthy krib. One of our in-stock kribs. Credit: Tropical Fish Co.
When your kribensis arrive — gentle acclimation, then let them settle
Kribensis are hardy travellers compared with soft-water cichlids, but they still arrive stressed and a calm acclimation pays off. Our delivery and on-arrival routine for a krib:
- Receive into calm. Quiet room, dim lights. Feel the bag — it should be close to your tank temperature. Don't open it yet.
- Float sealed, 15–20 minutes. Let the bag water and tank water match temperature before anything else.
- Drip-acclimate, about 30 minutes at roughly 2 drops per second. Kribs tolerate a wider range of water than rams, so they don't need the marathon 45-minute drip, but a steady drip still lets pH and hardness shift gently rather than in a jolt [6].
- Net, don't pour. Lift the krib out with a soft net into the tank — never tip shipping water into your aquarium.
- Lights off for a couple of hours, and don't feed for the first 24 hours. Give a new krib a cave to retreat to straight away — somewhere to feel secure speeds up settling.
A bonded male-and-female pair is the classic way to keep kribensis and the route to that brilliant cave-breeding behaviour [3]. But two kribs in a bag aren't automatically a pair, and two males can squabble. Either buy a known pair, or buy a small group of young fish in a roomier tank and let a pair form naturally — then you can rehome the spares. Remember the female is the one with the deeper, pink-flushing belly, so a slim, long-finned fish and a rounder, brighter-bellied fish is the combination you're after.
Common questions that decide success (and how to get them right)
A quick diagnostic table — what you might see, the likely cause, and the fix — because kribs are predictable once you know them:
| What you see | Most likely cause | What to do |
|---|---|---|
| A krib suddenly defending one corner | A pair has spawned in a cave | Normal and temporary — give other fish space; enjoy the parenting |
| Female glowing bright pink/purple underneath | She's in spawning condition | She's courting — a healthy sign, not illness |
| Plants near the cave uprooted | Pair tidying their breeding territory | Use rooted/attached plants (Anubias, Java fern) near caves |
| New krib hiding constantly | Settling in, or no cave to feel safe | Add a cave; lower lights; give it a week before worrying |
| All-male or all-female fry every spawn | Water pH skewing the sex ratio | Adjust pH of the fry-rearing water — softer for females, harder for males [2] |
There's only one thing to actively manage with kribensis, and it's the breeding territory. A guarding pair will chase fish — and sometimes each other — away from the cave, and in a small or under-decorated tank that pressure has nowhere to dissipate [3]. The fix is space and cover: an 80 L+ tank, multiple sightline breaks (wood, plants, rock), and tank mates that live in the upper water. Get that right and even a spawning krib pair is a pleasure, not a problem.
Related reading
Build the tank around the fish — these guides and pages take it further:
- Shop: African cichlids · Community tank fish
- Learn: Cichlid care guide · Water chemistry for UK keepers · Angelfish care guide
- Compare: Angelfish UK — the larger, more territorial South American centrepiece · Lake Malawi cichlids UK — the hard-water African alternative once you've got cichlid experience
If the kribensis hooks you on cichlids — and it usually does — the natural next steps are the bigger characters. The angelfish is the classic South American centrepiece, and the Lake Malawi cichlids are the colourful, hard-water Rift Lake fish that love the same tap water a krib does. But for your first cichlid, few fish reward a beginner like this little West African rainbow.
