Kribensis — Tank Size, Adult Size, Lifespan & Full Care Guide
Pelvicachromis pulcher
Care requirements at a glance
| Scientific name | Pelvicachromis pulcher |
|---|---|
| Group | Cichlid |
| Adult size | 4 in (10.2 cm) |
| Minimum tank | 20 gallons |
| Temperature | 75-82°F |
| pH | 6-7.5 |
| Hardness | 5-18 dGH |
| Temperament | Semi |
| Social | Pair / single |
| Diet | Omnivore |
| Swim level | Bottom |
| Care level | Easy |
| Lifespan | ~5 years |
How big do Kribensis get? Adult size explained
Kribensis are a mid-size species. This is the point where tank footprint starts to matter more than raw gallons — a long tank beats a tall one of the same volume. Adult kribensis reach 4.0 inches (10.2 cm). Fish you buy are almost always juveniles at roughly 1.8″, so plan the tank around the adult number, never the size in the bag.
| Stage | Typical length |
|---|---|
| Size sold in stores | about 1.8″ (4.6 cm) |
| Half-grown | 3.0″ (7.6 cm) at roughly 8 months |
| Full adult size | 4.0″ (10.2 cm) by 14 months |
| Sexual maturity | usually before full size, around 6–8 months |
Growth rate depends mostly on feeding quality and water changes in the first six months. Stunted growth from poor water does not make the fish 'stay small' safely — internal organs keep growing, which shortens lifespan considerably.
Kribensis tank size: minimum vs recommended
The 20-gallon figure is a floor, not a target. It assumes a cycled, filtered, planted tank and an owner who does weekly water changes.
Kribensis do not need a group, so 20 gallons genuinely works for a single specimen. Stepping up to 40 gallons mostly buys you stability and the option of tank mates.
| Tank size | Kribensis it supports | Verdict |
|---|---|---|
| 5 gallons | — | Too small |
| 10 gallons | — | Too small |
| 20 gallons | 4 | Workable minimum |
| 29 gallons | 6 | Workable minimum |
| 40 gallons | 8 | Comfortable |
| 55 gallons | 12 | Comfortable |
| 75 gallons | 16 | Comfortable |
Numbers assume kribensis are the main occupants with light additional stocking, a filter rated for the tank, and weekly 25–30% water changes. Use the stocking calculator to model a mixed community.
Kribensis group size: how many should you keep together?
Kribensis do not shoal and are comfortable alone. Many keepers do keep pairs or small groups; if you do, watch for one individual monopolising food or territory, and provide enough broken sight lines (plants, wood, rock) that a chased fish can break line of sight.
Kribensis water parameters
| Parameter | Range | Notes |
|---|---|---|
| Temperature | 75–82°F (24–28°C) | aim for 78°F and keep it stable |
| pH | 6–7.5 | target 6.8; stability beats the exact number |
| Hardness (GH) | 5–18 dGH | moderate to hard |
| Ammonia (NH₃) | 0 ppm | any reading means the tank is not cycled |
| Nitrite (NO₂) | 0 ppm | any reading is an emergency — water change now |
| Nitrate (NO₃) | under 20–40 ppm | controlled by water changes and live plants |
This species tolerates — and in fact prefers — harder water, which makes it a good match for most municipal tap water in the UK, US Midwest and much of Europe.
Stability matters more than perfection. A tank sitting steadily at pH 7.7 is healthier than one swinging between 6 and 7.5 every week. Test your tap water first, then choose fish that match it, rather than buying the fish and fighting the water afterwards.
Ideal kribensis tank setup
A 20-gallon tank with a pair, caves, and dense planting. Provide flat rocks for spawning. They are peaceful except when guarding fry. Keep with medium-sized tankmates that will not eat the fry.
| Substrate | Dark substrate brings out colour; the choice is otherwise up to you. |
|---|---|
| Planting | Plant the back and sides, leave open swimming space down the middle. |
| Flow | Moderate flow suits this species well. |
| Lighting | Moderate. Floating plants diffuse the light and make shy fish bolder. |
| Lid | Recommended — it also reduces evaporation and heat loss. |
What do Kribensis eat? Diet and feeding
Omnivores — flakes, pellets, frozen bloodworms, and blanched vegetables. Feed 1-2 times daily. They forage in the substrate and appreciate variety.
The single most common feeding error is quantity, not quality. Kribensis have a stomach roughly the size of their eye. Feed what disappears in about two minutes, once a day, and the tank stays clean.
Staple: quality flake or micro-pellet as the staple.
- Frozen daphnia or brine shrimp twice a week
- Blanched vegetable matter once a week
- Occasional live food for conditioning
| Frequency | What to do |
|---|---|
| Daily | One small feeding of quality flake or micro-pellet as the staple. Everything eaten within 2 minutes. |
| 2–3× weekly | Rotate in a second food type for variety and micronutrients. |
| Weekly | One fasting day gives the gut time to clear. Skip this for fry and for shrimp. |
Kribensis behaviour and temperament
Kribensis are semi-aggressive: peaceful most of the time, but they will defend a territory, especially while spawning. Plan for broken sight lines so a chased fish can escape. They spend most of their time in the substrate and lower third.
Signs of a settled, healthy specimen: strong colour, fins held open, active foraging, and a normal reaction to your hand near the glass. Signs of a stressed one: clamped fins, faded colour, hovering in a corner, gasping at the surface, or hiding constantly during daylight hours.
How long do Kribensis live?
| Factor | Effect on lifespan |
|---|---|
| Stable, cycled water | Adds years. The most common cause of early death in kribensis is ammonia exposure in an uncycled tank. |
| Correct temperature | Running warmer than 82°F speeds metabolism and shortens life; running cold invites disease. |
| Varied diet | Single-food diets cause organ problems and colour loss over time. |
| Right group size | Chronic aggression from a bad tank-mate match shortens lifespan. |
| Genetics | Mass-bred stock from large farms often lives noticeably shorter than quality or local stock. |
Kribensis tank mates: what works and what does not
Compatibility is decided by four things, in this order: water parameters (75–82°F, pH 6–7.5), adult size, temperament, and swimming level. A fish that matches on three and fails on one is not a match.
Avoid these
Check any pairing in the compatibility tool →
Breeding kribensis
Cave spawners that form pairs. Females become brightly colored (red belly) during breeding. Both parents guard eggs and fry. Fry are relatively large and easy to raise.
If you want fry to survive, the practical route is a separate, gently filtered grow-out tank. In a community tank almost every egg or fry becomes food, which is normal and not a sign that anything is wrong.
Male vs female kribensis
Males are larger (4") with pointed dorsal and anal fins. Females are smaller (3") with a rounded belly and bright red/purple belly during breeding. Females are more colorful when spawning.
Kribensis health, diseases and prevention
| Problem | What you see | What to do |
|---|---|---|
| Ich (white spot) | Salt-grain white dots, flicking against decor | Raise temperature slowly to 82°F and treat; aquarium salt is usually tolerated. |
| Fin rot | Ragged, receding or blackened fin edges | Almost always water quality. Increase water changes before reaching for medication. |
| Bloat / constipation | Swollen belly, stringy white waste | Fast 2–3 days, then feed blanched deshelled pea or daphnia. |
| Bacterial infection | Red streaks, ulcers, lethargy | Quarantine and treat with a broad-spectrum antibacterial; review water quality. |
| Stress / chronic hiding | Faded colour, clamped fins | Check parameters, group size and tank mates before medicating. |
Prevention beats treatment every time: quarantine new arrivals for two weeks, keep the tank understocked rather than at maximum capacity, and do a consistent weekly water change instead of a large emergency one every month.
First 30 days with Kribensis: a practical checklist
Most losses happen in the first month, and almost all of them are avoidable. This is the schedule we recommend.
| Before you buy | Do not add fish yet. The tank must be fully cycled: ammonia 0, nitrite 0, nitrate present. A cycled tank is the single biggest predictor of whether these animals survive. |
|---|---|
| Day 1 — acclimation | Float the bag 20 minutes to match temperature, then drip acclimate over 45–60 minutes. Never pour store water into your tank. |
| Days 1–3 | Lights off or dimmed. Do not feed on day one. Expect hiding and pale colour; this is normal. |
| Days 4–14 | Test ammonia and nitrite every second day — new stock is the classic trigger of a mini-cycle. Feed lightly. Watch that every individual is eating. |
| Days 14–30 | Colour should be full and behaviour settled. This is the window where ich typically shows up — check body condition from above, not just from the side. |
| After day 30 | Now you can add the next species. Adding stock in stages rather than all at once is what keeps the filter ahead of the bioload. |
Common mistakes when keeping Kribensis
- Buying juveniles for a small tank — Store specimens are a fraction of the 4.0″ adult size. The tank does not grow with them.
- Adding stock to an uncycled tank — Ammonia burns gills permanently. Cycle first, always — see our tank cycling guide.
- Overfeeding — Uneaten food becomes ammonia. Two minutes, once a day is the rule.
- Chasing pH with chemicals — pH adjusters cause swings that are far more dangerous than a stable pH slightly outside 6–7.5.
- Skipping quarantine — Two weeks in a separate tank prevents most disease outbreaks in an established display tank.
What does a kribensis setup cost?
| Item | Typical cost |
|---|---|
| Aquarium, 40 gal | $108 |
| Filter | $45 |
| Heater | $30 |
| Light | $55 |
| Substrate & decor | $46 |
| Liquid test kit | $32 |
| 1× kribensis | $8 |
| Estimated total | $324 |
Indicative US retail prices for a new setup. Running cost is modest: mostly electricity for the heater and filter, plus food and a water conditioner. Buying a larger tank up front is almost always cheaper than upgrading twice.
Kribensis compatibility: verdict per tank mate
Each pair below is a full comparison of temperature, pH, adult size and temperament. Green means compatible, amber means workable with conditions, red means avoid.
Open the full compatibility matrix
Kribensis FAQ
What size tank do kribensis need?
The minimum tank size for kribensis is 20 gallons (75 litres). We recommend 40 gallons or larger for stability and room for tank mates.
How big do kribensis get?
Adult kribensis reach 4.0 inches (10.2 cm). Store specimens are usually juveniles at around 1.8 inches, so always plan the tank around the adult size.
How long do kribensis live?
Kribensis typically live about 5 years in a well-maintained aquarium. Stable water quality and a varied diet are the two biggest factors in reaching the upper end of that range.
How many kribensis should I keep together?
Kribensis do not need a group and are content alone, though many keepers keep pairs or small groups successfully.
What water parameters do kribensis need?
Keep kribensis at 75–82°F (24–28°C), pH 6–7.5, and hardness 5–18 dGH. Ammonia and nitrite must both read zero at all times.
Are kribensis good for beginners?
Yes. Kribensis are rated easy to keep and are a solid choice for a first tank, provided it is fully cycled before they go in.
What do kribensis eat?
Omnivores — flakes, pellets, frozen bloodworms, and blanched vegetables. Feed 1-2 times daily. They forage in the substrate and appreciate variety.
Do kribensis need a heater?
Yes. Kribensis need 75–82°F, which is above typical room temperature. An adjustable heater sized to the tank is essential — temperature swings cause more disease than a slightly wrong average.
Do kribensis need a filter?
Yes. A filter houses the bacteria that convert ammonia to nitrate. Choose a filter rated for at least your tank volume, ideally a size up.
Can kribensis live alone?
Yes. Kribensis are perfectly content on their own and do not need company of their own kind.
What should you not keep with kribensis?
Avoid Neon Tetra, Ember Tetra, Endler's Livebearer, Pygmy Corydoras, Otocinclus, Celestial Pearl Danio. These are either large enough to eat them, aggressive enough to harass them, or need water parameters too far outside 75–82°F and pH 6–7.5.
Are kribensis aggressive?
Somewhat. Kribensis are semi-aggressive: usually calm, but territorial when spawning or when the tank is too small. Provide broken sight lines and enough floor space.
How do you tell male from female kribensis?
Males are larger (4") with pointed dorsal and anal fins. Females are smaller (3") with a rounded belly and bright red/purple belly during breeding. Females are more colorful when spawning.
Do kribensis breed in a home aquarium?
Cave spawners that form pairs. Females become brightly colored (red belly) during breeding. Both parents guard eggs and fry. Fry are relatively large and easy to raise.
Why are my kribensis hiding or losing colour?
In order of likelihood: the tank is not fully cycled (test ammonia and nitrite), the group is too small, the temperature is unstable, or a tank mate is harassing them. Fading colour is the earliest visible stress signal in this species — test the water before treating for anything.
How much does a kribensis setup cost?
Expect roughly $319 for a complete new 40-gallon setup including tank, filter, light, substrate, a test kit and the animals themselves. Buying the right size once is cheaper than upgrading twice.