Photo: User:Lerdsuwa (CC BY-SA 3.0) — via Wikimedia Commons
Rummy-nose Tetra (Hemigrammus rhodostomus)
A living compass: the tighter the school wheels, the better your water quality — rummy-noses tell you everything with their red noses.
Will it live with a Rummy-nose Tetra?
We compare each fish against your rummy-nose tetra 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)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Adolf's Cory 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)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- 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)
- Both are peaceful, and their water overlaps around 23–27 °C — no size, zone or temperament conflicts.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Bandit Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Bloodfin Tetra✅ CompatiblePeaceful · 5.5 cm · Easy care · 18–28 °C (64–82 °F)
- Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
- Checkered Barb✅ CompatiblePeaceful · 5 cm · Easy care · 20–25 °C (68–77 °F)
- Compatible on the things that matter: shared water near 23–25 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Checkered Barb in a shoal of 6+ or it gets stressed and nippy.
- Cherry Barb✅ CompatiblePeaceful · 5 cm · Easy care · 23–27 °C (73–81 °F)
- Both are peaceful, and their water overlaps around 23–27 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Cherry Barb in a shoal of 6+ or it gets stressed and nippy.
- Chocolate Gourami✅ CompatiblePeaceful · 5 cm · Hard care · 25–30 °C (77–86 °F)
- Both are peaceful, and their water overlaps around 25–29 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Chocolate Gourami in a shoal of 6+ or it gets stressed and nippy.
- Cochu's Blue Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Cochu's Blue Tetra in a shoal of 8+ or it gets stressed and nippy.
- Firehead Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Five-banded Barb✅ CompatiblePeaceful · 5 cm · Easy care · 23–27 °C (73–81 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Five-banded Barb in a shoal of 6+ or it gets stressed and nippy.
- Forktail Blue-eye✅ CompatiblePeaceful · 5 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Forktail Blue-eye in a shoal of 6+ or it gets stressed and nippy.
- Half-striped Penguin Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 23–28 °C (73–82 °F)
- Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Half-striped Penguin Tetra in a shoal of 6+ or it gets stressed and nippy.
- Harlequin Rasbora✅ CompatiblePeaceful · 5 cm · Easy care · 23–28 °C (73–82 °F)
- Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Harlequin Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Honey Gourami✅ CompatiblePeaceful · 5 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Horseman Cory✅ CompatiblePeaceful · 5 cm · Medium care · 22–26 °C (72–79 °F)
- Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Horseman Cory in a shoal of 6+ or it gets stressed and nippy.
- Japanese Trapdoor Snail✅ CompatiblePeaceful · 5 cm · Easy care · 10–28 °C (50–82 °F)
- Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Julii Corydoras✅ CompatiblePeaceful · 5 cm · Easy care · 23–26 °C (73–79 °F)
- Both are peaceful, and their water overlaps around 23–26 °C — no size, zone or temperament conflicts.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Julii Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Masked Corydoras✅ CompatiblePeaceful · 5 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Masked Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Mystery Snail✅ CompatiblePeaceful · 5 cm · Easy care · 20–28 °C (68–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Panda Corydoras✅ CompatiblePeaceful · 5 cm · Medium care · 20–26 °C (68–79 °F)
- Both are peaceful, and their water overlaps around 23–26 °C — no size, zone or temperament conflicts.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Panda Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Skunk Corydoras✅ CompatiblePeaceful · 5 cm · Easy care · 22–26 °C (72–79 °F)
- Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Skunk Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Stoliczka's Barb✅ CompatiblePeaceful · 5 cm · Easy care · 20–26 °C (68–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Stoliczka's Barb in a shoal of 6+ or it gets stressed and nippy.
- Xingu Black Neon Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 24–28 °C (75–82 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Xingu Black Neon Tetra in a shoal of 8+ or it gets stressed and nippy.
- Zebra Danio✅ CompatiblePeaceful · 5 cm · Easy care · 18–25 °C (64–77 °F)
- Compatible on the things that matter: shared water near 23–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Zebra Danio in a shoal of 6+ or it gets stressed and nippy.
- Amano Shrimp⚠️ With cautionPeaceful · 5 cm · Easy care · 18–28 °C (64–82 °F)
- Adult Amano Shrimp might survive with Rummy-nose Tetra, but expect the young to be eaten — plant heavily.
- Keep Rummy-nose Tetra 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)
- Black Ruby Barb and Rummy-nose Tetra are close in size, but the semi-aggressive one tends to dominate — add rummy-nose tetra in a group to spread the pressure.
- Your 75 L tank is below the ~100 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- 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)
- Expect Black Skirt Tetra to harass Rummy-nose Tetra at times; give dense cover and watch them at feeding.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Blue Turbo Snail⚠️ With cautionPeaceful · 5 cm · Medium care · 25–30 °C (77–86 °F)
- pH preferences only just meet (Rummy-nose Tetra 5.5–7 vs Blue Turbo Snail 7.5–8.5) — target the overlap and acclimate slowly.
- Keep Rummy-nose Tetra 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)
- Desert Goby is semi-aggressive and may chase or nip the smaller Rummy-nose Tetra — plant heavily and break up sight lines.
- Keep Rummy-nose 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 Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- 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)
- Expect Eastern Betta to harass Rummy-nose Tetra at times; give dense cover and watch them at feeding.
- Keep Rummy-nose 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)
- GloFish Tetra is semi-aggressive and may chase or nip the smaller Rummy-nose Tetra — plant heavily and break up sight lines.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep GloFish Tetra in a shoal of 6+ or it gets stressed and nippy.
- Humpbacked Tetra⚠️ With cautionSemi-aggressive · 5 cm · Hard care · 24–28 °C (75–82 °F)
- Expect Humpbacked Tetra to harass Rummy-nose Tetra at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Humpbacked Tetra in a shoal of 8+ or it gets stressed and nippy.
- Morse Code Corydoras⚠️ With cautionPeaceful · 5 cm · Medium care · 23–26 °C (73–79 °F)
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Morse Code Corydoras 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)
- Odessa Barb is semi-aggressive and may chase or nip the smaller Rummy-nose Tetra — plant heavily and break up sight lines.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
- Panda Loach⚠️ With cautionPeaceful · 6 cm · Hard care · 18–23 °C (64–73 °F)
- Different pH ranges (5.5–7 vs 7.2–8.2); doable if you sit in the shared band, but not ideal long-term.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Silvertip Tetra⚠️ With cautionSemi-aggressive · 5 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Silvertip Tetra to harass Rummy-nose Tetra at times; give dense cover and watch them at feeding.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Silvertip Tetra in a shoal of 6+ or it gets stressed and nippy.
- Spotfin Betta⚠️ With cautionSemi-aggressive · 5 cm · Medium care · 23–28 °C (73–82 °F)
- Spotfin Betta and Rummy-nose Tetra are close in size, but the semi-aggressive one tends to dominate — add rummy-nose tetra in a group to spread the pressure.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Striped Red-Eye Puffer⚠️ With cautionAggressive · 5 cm · Hard care · 24–28 °C (75–82 °F)
- Striped Red-Eye Puffer and Rummy-nose Tetra are close in size, but the aggressive one tends to dominate — add rummy-nose tetra in a group to spread the pressure.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Wine Red Betta⚠️ With cautionAggressive · 5 cm · Medium care · 24–28 °C (75–82 °F)
- Wine Red Betta is aggressive and may chase or nip the smaller Rummy-nose Tetra — plant heavily and break up sight lines.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Alligator Gar (250 cm) is big enough to swallow the 5 cm Rummy-nose Tetra whole.
- Alligator Gar clearly outsizes Rummy-nose Tetra and is aggressive; risky unless the tank is big and well-planted.
- Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Clown Knifefish (90 cm) is big enough to swallow the 5 cm Rummy-nose Tetra whole.
- Expect Clown Knifefish to harass Rummy-nose Tetra at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Size gap is too large (100 vs 5 cm): Fire Eel will treat Rummy-nose Tetra as food.
- Expect Fire Eel to harass Rummy-nose Tetra at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Koi (90 cm) is big enough to swallow the 5 cm Rummy-nose Tetra whole.
- One likes softer water and the other harder (2–8 vs 9–18 dGH) — a compromise, not a perfect match.
- Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Redtail Catfish (120 cm) is big enough to swallow the 5 cm Rummy-nose Tetra whole.
- Redtail Catfish is aggressive and may chase or nip the smaller Rummy-nose Tetra — plant heavily and break up sight lines.
- Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Spotted Gar (90 cm) is big enough to swallow the 5 cm Rummy-nose Tetra whole.
- Spotted Gar is aggressive and may chase or nip the smaller Rummy-nose Tetra — plant heavily and break up sight lines.
- Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Wels Catfish (300 cm) is big enough to swallow the 5 cm Rummy-nose Tetra whole.
- Wels Catfish clearly outsizes Rummy-nose Tetra and is aggressive; risky unless the tank is big and well-planted.
- Your 75 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Wolf Cichlid (72 cm) is big enough to swallow the 5 cm Rummy-nose Tetra whole.
- Wolf Cichlid clearly outsizes Rummy-nose Tetra and is aggressive; risky unless the tank is big and well-planted.
- Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
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.
Rummy-nose Tetra care specs
- Care level
- Medium
- Breeding
- Hard
- Max size
- 5 cm (2 in)
- Min tank size
- 75 L (19.8 gal)
- Temperature
- 23–29 °C (73–84 °F)
- pH
- 5.5–7
- Hardness
- 2–8 dGH
- Lifespan
- 5–8 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 6+ (shoaling)
- Family
- Characidae
- Origin
- South America — lower Rio Negro and Orinoco tributaries (Brazil, Venezuela)
What is a Rummy-nose Tetra?
The rummy-nose tetra (Hemigrammus rhodostomus) is one of the aquarium hobby’s most iconic schooling fish — and for good reason. Reaching just 5 cm (2 in) at maturity, this slender Characid punches well above its size with a striking tricolour pattern: a brilliant red blush covering the entire head and snout, a mirror-bright silver body, and a caudal fin boldly barred in black and white. No other small tetra wears quite the same combination, and when a group of eight or twelve wheels through open water in tight formation, the effect is genuinely spectacular.
What makes rummy-noses particularly valued by experienced keepers is their biological candour. The intensity of that red nose is a direct readout of water quality. In pristine, warm, soft water it burns like a stoplight; when nitrates climb, pH drifts or the tank gets stressed, the colour bleaches visibly within hours. They are, in effect, a living water-quality test. That sensitivity is also why they rate medium difficulty — they are not a fish for an uncycled tank or inconsistent maintenance.
Where do Rummy-nose Tetras come from?
Rummy-nose tetras are native to South America, specifically the blackwater tributaries of the lower Rio Negro and Orinoco systems in Brazil and Venezuela. These rivers flow through dense rainforest where decomposing leaf litter and driftwood release tannins and humic acids, staining the water the colour of weak tea. The result is water that is extraordinarily soft — often 1–4 dGH — acidic (pH as low as 4.5 in the wild), warm and very low in dissolved minerals. Light is filtered through the forest canopy, reaching the mid-water zone only dimly through overhanging vegetation.
Understanding this origin explains every element of good rummy-nose care. They evolved in slow, tannin-rich, chemically stable environments with virtually no hardness. Transplanting them into a bright, alkaline, hard-water community tank is asking them to tolerate conditions fundamentally unlike anything in their evolutionary history. They can adapt to pH up to 7.0, but the closer you get to their blackwater roots, the more vivid the colour, the tighter the school, and the longer the lifespan.
What size tank does a Rummy-nose Tetra need?
The minimum practical tank size is 75 litres (20 gallons). This is not a case where the minimum is generous — rummy-noses are fast, active mid-water swimmers that cover the full length of the tank in synchronised bursts. A 75 L tank gives a group of six to eight fish enough horizontal swimming room to behave naturally, while also providing the water volume needed to keep chemistry stable.
A longer footprint is always preferable to a taller one: a 90 cm (36 in) tank at 90–110 L is a much better home than a tall, narrow 80 L column. Add a secure, well-fitting lid — these fish can and do jump, particularly during water changes or when startled. Keep the filter return baffled to gentle flow; although they come from rivers, the tributaries they inhabit move slowly compared to open-channel flow, and a powerful current will scatter their schooling behaviour.
What water parameters do Rummy-nose Tetras need?
Rummy-noses are among the more demanding tetras when it comes to water chemistry. The target parameters drawn directly from their wild habitat are:
- Temperature: 23–29 °C (73–84 °F), with 25–27 °C (77–81 °F) as the day-to-day sweet spot.
- pH: 5.5–7.0, ideally 6.0–6.8 for sustained colouration and health.
- Hardness: 2–8 dGH — genuinely soft water. Very hard tap water will need treatment.
Because these fish come from chemically stable blackwater environments, consistency matters as much as the numbers themselves. A tank that holds pH 6.5 steadily is better than one that drifts between 6.0 and 7.2. Perform weekly partial water changes of 25–30%, use a quality test kit, and consider adding Indian almond leaves or peat filtration to buffer softness and introduce mild tannins. Keep nitrates under 20 ppm at all times — rummy-noses will telegraph rising nitrates with fading red before a test kit alarming you.
What do Rummy-nose Tetras eat?
Rummy-nose tetras are omnivores with a modest natural diet of tiny invertebrates, zooplankton and plant matter found in the water column. In the aquarium they are undemanding and unfussy feeders. A quality small-particle flake or micro-pellet should form the staple, offered once or twice daily in amounts eaten within two minutes.
Supplement regularly with frozen or live foods to maintain peak colour and condition: daphnia, baby brine shrimp, micro worms and finely chopped bloodworms are all accepted readily. Variety keeps their immune system strong and brings out the full intensity of the red nose. Avoid overfeeding — uneaten food degrades water quality rapidly in the soft, low-mineral water these fish need. A single feeding missed each week does no harm and keeps the tank cleaner.
Are Rummy-nose Tetras peaceful — and what fish can live with them?
Rummy-nose tetras are thoroughly peaceful and one of the safest choices for a soft-water community tank. They show no aggression toward other species and are not fin-nippers, which makes them suitable companions for fish with delicate finnage. Their only requirement is that tankmates share their preference for warm, soft, slightly acidic water — pairing them with hard-water species is a compromise that shortchanges both fish.
Excellent companions include cardinal tetras, ember tetras, corydoras catfish (especially C. sterbai, which tolerates the same warm temperatures), dwarf cichlids (apistogrammas and German blue rams), small rasboras, and pencilfish. Avoid nippy species like tiger barbs, hard-water livebearers, or any fish large enough to swallow a 5 cm tetra. Because rummy-noses occupy the mid-water zone, a mix of surface, bottom, and mid-level species produces a full, naturalistic display without overcrowding any one layer.
For a complete, curated list of compatible and incompatible species, see Rummy-nose Tetra tank mates.
How do you tell male and female Rummy-nose Tetras apart?
Sexual dimorphism in rummy-nose tetras is subtle — this is not a species where sexing from across the room is possible. Females are slightly fuller in the belly, particularly when carrying eggs, giving them a more rounded profile viewed from above or from the side. Males are slimmer and somewhat more streamlined.
The differences are best assessed from above with the fish in good condition in established water. When females are ripe and gravid, the distinction becomes noticeably clearer. Outside of breeding condition, many individuals are genuinely difficult to sex with confidence, especially in younger fish. Most keepers simply maintain a mixed group of six or more and allow natural pairings to form.
How do Rummy-nose Tetras breed?
Rummy-nose tetras are rated hard to breed in captivity, and that rating is honest. Successful spawning requires conditions close to their wild blackwater habitat: very soft water (1–4 dGH), pH around 5.5–6.5, and a dedicated breeding tank separate from the display. A small, dimly lit tank of 30–40 L with java moss, a fine-leaved spawning mop and a sponge filter is the standard setup.
Condition a pair (or small group) with high-protein live and frozen foods for two to three weeks, then introduce them to the breeding tank. Spawning is a scattered egg affair — the female broadcasts adhesive eggs among fine plants and the parents show no further interest, and will eat the eggs if given the chance. Remove adults promptly after spawning. Eggs hatch in roughly 24–36 hours; fry are extremely small and require infusoria or commercial first-foods before graduating to baby brine shrimp at around a week old. Water quality in the fry tank must be immaculate. This is a project for experienced breeders willing to dedicate equipment and time.
What are common Rummy-nose Tetra diseases?
Rummy-nose tetras are not especially disease-prone in a well-maintained, species-appropriate tank, but their sensitivity to water quality makes them early victims when conditions slip. The most common issues are:
- Ich (white spot): Fine white specks on the body and fins, often triggered by chilling or sudden temperature drops. Stable, appropriately warm water is the primary prevention.
- Neon tetra disease: Despite the name, this bacterial infection (caused by Pleistophora hyphessobryconis) affects multiple tetra species, causing colour loss and muscle wasting. Quarantining all new fish before introducing them is the best defence.
- Fin rot and bacterial infections: Secondary to poor water quality. Weekly water changes and keeping nitrates low prevent the vast majority of cases.
- Intestinal parasites: Internal worms can cause thinning and loss of condition. Quarantine new stock and source fish from reputable suppliers.
Prevention in every case comes back to the same fundamentals: a cycled tank, soft and stable water, consistent water changes, and quarantining all new fish for two to four weeks before introduction.
Health note: symptoms of different diseases often overlap and can be difficult to distinguish visually. Always confirm your diagnosis against a reputable aquatic veterinary or fish-health resource before choosing any treatment.
How long do Rummy-nose Tetras live?
In good conditions, rummy-nose tetras live 5–8 years — a notably long lifespan for a small tetra. The key phrase is “good conditions”: this species rewards precision. A tank that runs warm, soft, clean and stable will see fish reach the top of that range; a tank where parameters fluctuate or nitrates creep up will see shorter lifespans and chronically faded colouration.
Because they are shoaling fish, their wellbeing is also tied to group size. A school of eight or more in a planted, well-maintained tank is a very different animal from three fish crammed into a bright, hard-water community. Get the group size, the water, and the tankmates right, and rummy-nose tetras will be one of the most visually rewarding and long-lived small fish you can keep.
Frequently asked questions
How many rummy-nose tetras should I keep together?
Keep at least six, but eight or more is strongly recommended. This species is famous for tight, synchronised schooling — the larger the group, the more dramatic the display. Fewer than six causes stress, faded colouration and increased hiding. In a 75 L tank eight fish is a sensible target; in 120 L you can comfortably run twelve or more.
Why are my rummy-nose tetras losing their red colour?
Colour fade is almost always a water-quality signal. Their brilliant red nose brightens in pristine, warm, soft water and washes out when nitrates climb, pH swings, or temperature drops. Check parameters first: aim for nitrates under 20 ppm, pH 6.0–7.0, and temperature 25–28 °C. Stress from a too-small group or aggressive tankmates can also bleach the nose.
What you need to keep a rummy-nose tetra
The baseline is a heated, filtered 75 L+ tank: a reliable heater to hold 23–29 °C (73–84 °F), a gentle filter that won't batter a rummy-nose tetra in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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