Photo: DefenderRegina (CC BY-SA 3.0) — via Wikimedia Commons
Peaceful Betta (Betta imbellis)
The low-aggression betta that can actually live with tank-mates — a subtler gem for the planted nano tank.
Will it live with a Peaceful Betta?
We compare each fish against your peaceful betta on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Adolf's Cory✅ CompatiblePeaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Adolf's Cory in a shoal of 6+ or it gets stressed and nippy.
- Agassiz's Corydoras✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Axelrod's Cory✅ CompatiblePeaceful · 5 cm · Easy care · 23–28 °C (73–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Axelrod's Cory in a shoal of 6+ or it gets stressed and nippy.
- Bandit Corydoras✅ CompatiblePeaceful · 5 cm · Easy care · 22–27 °C (72–81 °F)
- Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Bandit Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Blood Red Tiger Pleco✅ CompatiblePeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Blue Turbo Snail✅ CompatiblePeaceful · 5 cm · Medium care · 25–30 °C (77–86 °F)
- Compatible on the things that matter: shared water near 25–28 °C, workable temperaments, and no predator-and-prey size gap.
- Butterfly Hillstream Loach✅ CompatiblePeaceful · 6 cm · Hard care · 18–24 °C (64–75 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–24 °C — no size, zone or temperament conflicts.
- Celebes Rainbowfish✅ CompatiblePeaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Celebes Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Corydoras Catfish✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Keep Corydoras Catfish in a shoal of 6+ or it gets stressed and nippy.
- Costa's Tetra✅ CompatiblePeaceful · 7 cm · Easy care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Keep Costa's Tetra in a shoal of 6+ or it gets stressed and nippy.
- Duplicareus Corydoras✅ CompatiblePeaceful · 5.5 cm · Medium care · 23–27 °C (73–81 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–27 °C — no size, zone or temperament conflicts.
- Keep Duplicareus Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Elegant Cory✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Keep Elegant Cory in a shoal of 6+ or it gets stressed and nippy.
- False Julii Corydoras✅ CompatiblePeaceful · 6 cm · Easy care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Keep False Julii Corydoras in a shoal of 6+ or it gets stressed and nippy.
- German Blue Ram✅ CompatiblePeaceful · 6 cm · Hard care · 27–30 °C (81–86 °F)
- Compatible on the things that matter: shared water near 27–28 °C, workable temperaments, and no predator-and-prey size gap.
- Hillstream Loach✅ CompatiblePeaceful · 6 cm · Hard care · 20–24 °C (68–75 °F)
- Compatible on the things that matter: shared water near 24–24 °C, workable temperaments, and no predator-and-prey size gap.
- Narcissus II Cory✅ CompatiblePeaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Keep Narcissus II Cory in a shoal of 6+ or it gets stressed and nippy.
- Peacock Gudgeon✅ CompatiblePeaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Peppered Corydoras✅ CompatiblePeaceful · 7 cm · Easy care · 18–26 °C (64–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Keep Peppered Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Rio Negro Checkerboard Cichlid✅ CompatiblePeaceful · 7 cm · Hard care · 24–29 °C (75–84 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Rust Corydoras✅ CompatiblePeaceful · 5.5 cm · Easy care · 23–27 °C (73–81 °F)
- Compatible on the things that matter: shared water near 24–27 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rust Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Slate Corydoras✅ CompatiblePeaceful · 6 cm · Medium care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Slate Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Spotfin Corydoras✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Spotfin Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Spotted Corydoras✅ CompatiblePeaceful · 7 cm · Easy care · 22–27 °C (72–81 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Spotted Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Sterbai Corydoras✅ CompatiblePeaceful · 6.5 cm · Medium care · 24–30 °C (75–86 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Black Ruby Barb⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 22–26 °C (72–79 °F)
- Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
- Your 75 L tank is below the ~100 L this pairing really wants — crowding raises aggression.
- Keep Black Ruby Barb in a shoal of 6+ or it gets stressed and nippy.
- Black Skirt Tetra⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
- Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Blackline Rasbora⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Peaceful Betta to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
- Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Desert Goby⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 18–28 °C (64–82 °F)
- Peaceful Betta and Desert Goby can both be territorial; doable with space and dense planting, but watch for chasing.
- Diamond Tetra⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Peaceful Betta to harass Diamond Tetra at times; give dense cover and watch them at feeding.
- Keep Diamond Tetra in a shoal of 6+ or it gets stressed and nippy.
- Dwarf Chain Loach⚠️ With cautionPeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Dwarf Chain Loach in a shoal of 6+ or it gets stressed and nippy.
- Eastern Betta⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
- Peaceful Betta and Eastern Betta can both be territorial; doable with space and dense planting, but watch for chasing.
- Peaceful Betta and Eastern Betta are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
- Glass Bloodfin Tetra⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Peaceful Betta to harass Glass Bloodfin Tetra at times; give dense cover and watch them at feeding.
- Keep Glass Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
- GloFish Tetra⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 21–28 °C (70–82 °F)
- Peaceful Betta and GloFish Tetra can both be territorial; doable with space and dense planting, but watch for chasing.
- Keep GloFish Tetra in a shoal of 6+ or it gets stressed and nippy.
- Guppy⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Peaceful Betta to harass Guppy at times; give dense cover and watch them at feeding.
- Neon Dwarf Rainbowfish⚠️ With cautionPeaceful · 6 cm · Easy care · 23–27 °C (73–81 °F)
- Peaceful Betta is semi-aggressive and may chase or nip the smaller Neon Dwarf Rainbowfish — plant heavily and break up sight lines.
- Keep Neon Dwarf Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Odessa Barb⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
- Peaceful Betta and Odessa Barb can both be territorial; doable with space and dense planting, but watch for chasing.
- Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
- Pearl Danio⚠️ With cautionPeaceful · 6 cm · Easy care · 20–25 °C (68–77 °F)
- Peaceful Betta is semi-aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Platy⚠️ With cautionPeaceful · 6 cm · Easy care · 21–28 °C (70–82 °F)
- Peaceful Betta and Platy are close in size, but the semi-aggressive one tends to dominate — add platy in a group to spread the pressure.
- Samurai Gourami⚠️ With cautionPeaceful · 6 cm · Hard care · 24–28 °C (75–82 °F)
- Expect Peaceful Betta to harass Samurai Gourami at times; give dense cover and watch them at feeding.
- Peaceful Betta and Samurai Gourami are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
- Three-striped Dwarf Cichlid⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 23–29 °C (73–84 °F)
- Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Peaceful Betta and Alligator Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Size gap is too large (250 vs 6 cm): Alligator Gar will treat Peaceful Betta as food.
- Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Two assertive fish, one genuinely aggressive: Peaceful Betta and Clown Knifefish will hold territory and clash.
- Size gap is too large (90 vs 6 cm): Clown Knifefish will treat Peaceful Betta as food.
- Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Size gap is too large (100 vs 6 cm): Fire Eel will treat Peaceful Betta as food.
- Peaceful Betta and Fire Eel can both be territorial; doable with space and dense planting, but watch for chasing.
- Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Peaceful Betta is bite-sized to a 90 cm koi — it will be eaten.
- Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Peaceful Betta and Redtail Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Size gap is too large (120 vs 6 cm): Redtail Catfish will treat Peaceful Betta as food.
- Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Peaceful Betta and Spotted Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Size gap is too large (90 vs 6 cm): Spotted Gar will treat Peaceful Betta as food.
- Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Peaceful Betta and Wels Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Wels Catfish (300 cm) is big enough to swallow the 6 cm Peaceful Betta whole.
- Your 75 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Two assertive fish, one genuinely aggressive: Peaceful Betta and Wolf Cichlid will hold territory and clash.
- Size gap is too large (72 vs 6 cm): Wolf Cichlid will treat Peaceful Betta as food.
- Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.
Peaceful Betta care specs
- Care level
- Medium
- Breeding
- Medium
- Max size
- 6 cm (2.4 in)
- Min tank size
- 40 L (10.6 gal)
- Temperature
- 24–28 °C (75–82 °F)
- pH
- 5.5–7.5
- Hardness
- 1–10 dGH
- Lifespan
- 3–5 years
- Diet
- Carnivore
- Swim level
- Top
- Group size
- Best alone or in a pair
- Family
- Osphronemidae
- Origin
- Southeast Asia — Thailand, peninsular Malaysia, and Singapore; blackwater peat swamp forest streams
What is a Peaceful Betta?
The Peaceful Betta (Betta imbellis), also called the Crescent Betta, is a wild-type labyrinth fish native to the blackwater peat swamp forests of Southeast Asia. It reaches up to 6 cm (2.4 in) and wears a dark iridescent body with the species’ signature red and blue crescent markings along the tail and fin edges — understated compared to fancy Betta splendens strains, but striking in tannin-stained water.
The key distinction from its domesticated cousin is temperament. Males are still territorial enough to be classed as semi-aggressive, but the aggression is genuinely milder toward dissimilar fish, making B. imbellis a viable choice for planted nano community tanks where B. splendens would cause problems. Like all bettas it possesses a labyrinth organ for breathing atmospheric air, which allows it to thrive in the warm, low-oxygen swamp water of its natural range.
Where does the Peaceful Betta come from?
Betta imbellis originates from the lowland coastal plains of Thailand, peninsular Malaysia, and Singapore. Its native habitat is blackwater peat swamp forest streams: water stained amber-brown with tannins from decomposing leaf litter, extremely soft (1–10 dGH), low pH (often 4–6 in the wild), dim light, and dense vegetation. This is the reverse of a standard tap-water aquarium and sets the template for good care.
Much of this habitat has been lost to agriculture, making the species increasingly valued among wild-type Betta collectors. Tank-bred specimens may tolerate a slightly wider pH range, but all do best in soft, acidic, tannin-rich setups.
What tank setup and size does a Peaceful Betta need?
A minimum of 40 litres (10 gallons) suits a single specimen; a pair or a one-male, two-female group does better in 60–75 L (16–20 gal) with enough planted territory to separate individuals. Choose a tank that is longer than tall — B. imbellis is a top-dweller that must reach the surface to breathe. Keep water a few centimetres below the rim and always use a lid, as bettas jump.
Replicate the peat swamp in the decor. Indian almond (Catappa) leaves on the substrate leach tannins and provide cover; driftwood and dense stem planting create broken sightlines that reduce male aggression. Floating plants such as frogbit diffuse light and anchor bubble nests. Flow must be very gentle — a sponge filter is the standard choice. Powerheads and hang-on-back filters generate currents that stress this fish and erode its fins.
What water parameters does a Peaceful Betta need?
- Temperature: 24–28 °C (75–82 °F). A heater is essential; do not rely on ambient room temperature in most climates.
- pH: 5.5–7.5. Wild specimens live well below this range, and pH 6.0–7.0 is a practical target. Adding Indian almond leaves or peat filtration drives pH down gently without chemicals.
- Hardness: 1–10 dGH. Soft water is not optional for long-term health and breeding — use RO water blended with tap if your tap water is hard.
Stability is more important than hitting any single number. Cycle the tank fully before introducing fish, test weekly while the setup is maturing, and carry out 25–30% water changes weekly using temperature-matched, dechlorinated water of similar softness to avoid shocking the fish. Tannin-stained water that looks “dirty” to a newcomer is exactly right for this species.
What does a Peaceful Betta eat?
Betta imbellis is a carnivore that feeds naturally on small invertebrates, insect larvae, and zooplankton at and near the water surface. In the aquarium a diet of quality micro pellets or small betta pellets forms the nutritional staple, but variety keeps the fish in peak condition: rotate in frozen or live bloodworms, daphnia, brine shrimp, and mosquito larvae. Frozen foods are convenient and safe; live foods trigger the most natural feeding response and are especially useful before breeding attempts.
Feed once or twice daily in small amounts the fish can consume within two minutes. Remove any uneaten food promptly to avoid fouling the water. A brief fast one day per week prevents the digestive issues — bloat in particular — that come from consistent overfeeding. This is a small-stomached fish that begs convincingly; resist the habit of overfeeding it.
How does the Peaceful Betta behave, and what are good tank-mates?
True to its name, B. imbellis is measurably calmer than Betta splendens. Males display and flare at rivals but are less likely to escalate to sustained fin-shredding against dissimilar fish. This makes a wider range of community arrangements possible, though “peaceful” is relative — this is still a semi-aggressive labyrinth fish, not a docile community species.
Males must be watched carefully together; two males in a standard nano tank will fight. A single male with two or more females in a well-planted tank is often workable if the females have ample cover and the keeper monitors for chronic chasing.
Good tank-mate profiles: small, calm bottom- and mid-dwellers that stay out of the surface zone — pygmy corydoras, otocinclus, small rasboras (chili rasboras, phoenix rasboras), and diminutive danios are frequently successful. Avoid fin-nippers (tiger barbs, many tetras at small group sizes), bright-coloured long-finned species that may trigger territorial responses, and any fish large enough to bully or eat a 6 cm betta.
For a full, filterable list of tested pairings, see Peaceful Betta tank mates.
How do you tell male and female Peaceful Bettas apart?
Sexing mature B. imbellis is straightforward. Males are more intensely coloured, with larger fins and a vivid, well-defined crescent on the caudal fin; they display readily at rivals. Females are smaller, shorter-finned, paler, and show a white ovipositor (egg spot) between the ventral fins when ripe. Juveniles are harder to sex — wait until at least 3–4 months old. In breeding groups, keep two or three females per male to diffuse aggression.
How do Peaceful Bettas breed?
Betta imbellis is a bubble-nest builder rated medium difficulty. Condition both sexes on live or frozen foods for one to two weeks, then introduce the female to the male’s tank with water at pH 6.0–6.5 and 26–28 °C (79–82 °F). Floating plants give the male anchor points for nest construction.
The male flares and displays; a receptive female shows vertical barring. He wraps around her to fertilise eggs, then catches each egg and deposits it in the nest. Once spawning is complete, remove the female — the male guards the nest alone and may attack her. Fry are free-swimming within two days. Start them on infusoria or fine commercial fry food, graduating to baby brine shrimp as they grow.
What diseases affect Peaceful Bettas?
The disease profile mirrors other Betta species:
- Fin rot — bacterial erosion of fin edges; almost always a water-quality problem.
- Ich (white spot) — white grains on body and fins; triggered by temperature stress or infected new arrivals.
- Velvet (Oodinium) — fine gold dust visible under a flashlight; highly contagious; quarantine immediately.
- Bloat / constipation — rounded abdomen from overfeeding; fasting and daphnia often help mild cases.
- Columnaris — cottony lesions following handling stress or fin-nipping injuries.
Prevention: cycle the tank before stocking, quarantine all new fish for two to four weeks, maintain stable soft warm water, and avoid overfeeding.
Health note: medication dosing and disease diagnosis are beyond the scope of a care profile. Confirm symptoms against a veterinary or specialist fish-health source before treating — many betta diseases look similar.
How long does a Peaceful Betta live?
With good care B. imbellis lives 3–5 years. The species is less commonly sold through mass-market pet chains, so buyers typically receive younger fish than with B. splendens — a small advantage. A tannin-rich, soft, warm, well-maintained tank, a varied diet, and consistent water changes are the factors that determine whether a Peaceful Betta reaches the top of that range.
Frequently asked questions
Is the Peaceful Betta really peaceful enough for a community tank?
More so than Betta splendens, yes — pairs can sometimes be kept together and males are less likely to attack dissimilar tank-mates. That said, males still fight each other and should not be kept together long-term without a very large, well-planted tank. Choose calm, small tank-mates that do not fin-nip.
What makes the water so important for Betta imbellis?
In the wild it inhabits blackwater swamps: soft, highly acidic water stained with tannins from leaf litter. Replicating this — low pH, very soft water, dim light, and tannin-rich decor — not only keeps the fish healthy but triggers its best colour and encourages breeding.
What you need to keep a peaceful betta
The baseline is a heated, filtered 40 L+ tank: a reliable heater to hold 24–28 °C (75–82 °F), a gentle filter that won't batter a peaceful betta in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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