Photo: User:Lerdsuwa (CC BY-SA 3.0) — via Wikimedia Commons
Firehead Tetra (Hemigrammus bleheri)
A tight-schooling tetra whose blazing red head and mirrored tail band turn any planted tank into a living river.
Will it live with a Firehead Tetra?
We compare each fish against your firehead 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)
- Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Firehead Tetra in a shoal of 8+ 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)
- Both are peaceful, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Keep Firehead Tetra in a shoal of 8+ 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Firehead Tetra in a shoal of 8+ 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 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 Firehead Tetra in a shoal of 8+ 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)
- Both are peaceful, and their water overlaps around 24–25 °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 Firehead Tetra in a shoal of 8+ 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 24–27 °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 Firehead Tetra in a shoal of 8+ 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; 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 Firehead Tetra in a shoal of 8+ 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)
- 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 Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Cochu's Blue 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, and their water overlaps around 24–27 °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 Firehead Tetra in a shoal of 8+ 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)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Firehead Tetra in a shoal of 8+ 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)
- 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 Firehead Tetra in a shoal of 8+ 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; 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 Firehead Tetra in a shoal of 8+ 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)
- 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 Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Horseman Cory✅ CompatiblePeaceful · 5 cm · Medium care · 22–26 °C (72–79 °F)
- Both are peaceful, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Keep Firehead Tetra in a shoal of 8+ 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 24–28 °C — no size, zone or temperament conflicts.
- Keep Firehead Tetra in a shoal of 8+ 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 24–26 °C — no size, zone or temperament conflicts.
- Keep Firehead Tetra in a shoal of 8+ 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 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Firehead Tetra in a shoal of 8+ 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)
- Both are peaceful, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Panda Corydoras✅ CompatiblePeaceful · 5 cm · Medium 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.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Panda Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Rummy-nose Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 23–29 °C (73–84 °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 Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Rummy-nose Tetra in a shoal of 6+ or it gets stressed and nippy.
- Skunk Corydoras✅ CompatiblePeaceful · 5 cm · Easy care · 22–26 °C (72–79 °F)
- Both are peaceful, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra in a shoal of 8+ 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)
- 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 Firehead Tetra in a shoal of 8+ 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 24–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Firehead Tetra in a shoal of 8+ 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)
- Firehead Tetra may eat Amano Shrimp or pick off its shrimplets — a densely planted tank with moss gives them a fighting chance.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra are close in size, but the semi-aggressive one tends to dominate — add firehead 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 Firehead Tetra in a shoal of 8+ 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)
- Black Skirt Tetra is semi-aggressive and may chase or nip the smaller Firehead Tetra — plant heavily and break up sight lines.
- Keep Firehead Tetra in a shoal of 8+ 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)
- Different pH ranges (6–7 vs 7.5–8.5); doable if you sit in the shared band, but not ideal long-term.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra — plant heavily and break up sight lines.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra in a shoal of 8+ 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 Firehead Tetra at times; give dense cover and watch them at feeding.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra — plant heavily and break up sight lines.
- Keep Firehead Tetra in a shoal of 8+ 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)
- Humpbacked Tetra and Firehead Tetra are close in size, but the semi-aggressive one tends to dominate — add firehead tetra in a group to spread the pressure.
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra in a shoal of 8+ 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 and Firehead Tetra are close in size, but the semi-aggressive one tends to dominate — add firehead tetra in a group to spread the pressure.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
- Peaceful Betta⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
- Expect Peaceful Betta to harass Firehead Tetra at times; give dense cover and watch them at feeding.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra at times; give dense cover and watch them at feeding.
- Keep Firehead Tetra in a shoal of 8+ 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 is semi-aggressive and may chase or nip the smaller Firehead Tetra — plant heavily and break up sight lines.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Striped Red-Eye Puffer⚠️ With cautionAggressive · 5 cm · Hard care · 24–28 °C (75–82 °F)
- Expect Striped Red-Eye Puffer to harass Firehead Tetra at times; give dense cover and watch them at feeding.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Wine Red Betta⚠️ With cautionAggressive · 5 cm · Medium care · 24–28 °C (75–82 °F)
- Wine Red Betta and Firehead Tetra are close in size, but the aggressive one tends to dominate — add firehead tetra in a group to spread the pressure.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Size gap is too large (250 vs 5 cm): Alligator Gar will treat Firehead Tetra as food.
- Expect Alligator Gar to harass Firehead Tetra at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra whole.
- Expect Clown Knifefish to harass Firehead 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 Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Fire Eel (100 cm) is big enough to swallow the 5 cm Firehead Tetra whole.
- Expect Fire Eel to harass Firehead 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 Firehead Tetra in a shoal of 8+ 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 Firehead Tetra whole.
- Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Keep Firehead Tetra in a shoal of 8+ 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 Firehead Tetra whole.
- Redtail Catfish clearly outsizes Firehead Tetra and is aggressive; risky unless the tank is big and well-planted.
- Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Size gap is too large (90 vs 5 cm): Spotted Gar will treat Firehead Tetra as food.
- Expect Spotted Gar to harass Firehead Tetra at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Firehead Tetra is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
- Wels Catfish is aggressive and may chase or nip the smaller Firehead Tetra — plant heavily and break up sight lines.
- Your 75 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Size gap is too large (72 vs 5 cm): Wolf Cichlid will treat Firehead Tetra as food.
- Wolf Cichlid is aggressive and may chase or nip the smaller Firehead Tetra — plant heavily and break up sight lines.
- Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
- Keep Firehead Tetra in a shoal of 8+ 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.
Firehead Tetra care specs
- Care level
- Medium
- Breeding
- Hard
- Max size
- 5 cm (2 in)
- Min tank size
- 75 L (19.8 gal)
- Temperature
- 24–28 °C (75–82 °F)
- pH
- 6–7
- Hardness
- 2–10 dGH
- Lifespan
- 3–5 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 8+ (shoaling)
- Family
- Characidae
- Origin
- South America — upper Rio Negro and Orinoco basin (Brazil, Venezuela, Colombia)
What is a Firehead Tetra?
The Firehead Tetra (Hemigrammus bleheri) is the species actually behind most “Rummy-nose Tetra” labels at your local fish store. Reaching 5 cm (2 in), it carries an immediately recognisable pattern: a scarlet cap that begins at the snout and bleeds past the gill cover onto the upper body, paired with a bold black-and-white chevron on the forked caudal fin.
What makes this fish genuinely useful beyond its looks is that the red intensity acts as a live water-quality readout. A school in clean, warm, soft, slightly acidic water glows; let the pH drift up or keep too few fish together and the colour washes out almost overnight — making it one of the hobby’s most reliable “canary” fish.
Three species share the Rummy-nose name: H. bleheri (Firehead Tetra), H. rhodostomus (true Rummy-nose) and Petitella georgiae (False Rummy-nose). H. bleheri is the hardiest, most widely available, and the one this guide covers.
Where do Firehead Tetras come from?
Wild Firehead Tetras come from the upper Rio Negro and Orinoco basin — blackwater and clearwater river systems across Brazil, Venezuela and Colombia. The Rio Negro runs the colour of dark tea from dissolved tannins; pH can dip below 5.0 in flooded forest zones, hardness is negligible and temperatures are stable in the mid-to-upper 20s °C year-round.
That origin reframes care priorities: this is not a fish that thrives long-term in hard, alkaline tap water. The closer you mirror blackwater conditions — soft, warm, slightly acidic, tannin-tinted — the more confident, colourful and long-lived your school will be.
What size tank does a Firehead Tetra need?
The practical minimum is 75 litres (20 gallons), and that figure assumes the minimum school of eight. Firehead Tetras are open-water mid-column swimmers that move constantly and need lateral swimming length to express natural schooling behaviour. A tank that is long and relatively shallow works better than a tall cube — target at least 60 cm (24 in) of horizontal run.
Key setup elements:
- Dark substrate — fine black sand or dark gravel intensifies the red colouration by suppressing light scatter from below.
- Floating or large-leaf surface plants — diffuse overhead light and reduce skittishness.
- Gentle current — a turnover of 4–6× tank volume per hour is plenty; these fish are not strong swimmers.
- Driftwood and Indian almond leaves — leach tannins that lower pH naturally; optional but genuinely beneficial.
- Dense side and back planting — provides a visual refuge, but keep the centre open for schooling.
A tightly fitting lid is advisable: startled schools will occasionally jump.
What water parameters do Firehead Tetras need?
- Temperature: 24–28 °C (75–82 °F). The sweet spot is around 25–26 °C; higher temperatures raise metabolism and shorten lifespan.
- pH: 6.0–7.0. Below 6.5 is ideal for long-term condition; above 7.0 causes gradual colour loss and stress.
- Hardness: 2–10 dGH. Soft water is strongly preferred; if your tap water is hard, consider RO dilution or a dedicated soft-water mix.
- Ammonia / Nitrite: 0 ppm — non-negotiable. The tank must be fully cycled before fish are added.
- Nitrate: keep below 20 ppm with regular water changes; Firehead Tetras are sensitive to accumulated nitrate.
Weekly partial water changes of 20–30% using temperature-matched, dechlorinated water maintain the parameter stability this species needs. Sudden shifts — even in a favourable direction — stress the school and trigger colour loss.
What do Firehead Tetras eat?
Firehead Tetras are omnivores with a preference for small protein-rich foods. A practical rotation: quality micro-pellets or small tropical flakes as the daily staple, supplemented 2–3 times per week with frozen or live daphnia, baby brine shrimp or cyclops. Spirulina-enriched flakes round out the vegetable component.
Feed only what the school can finish in two minutes, once or twice daily, and skip one day per week. Overfeeding is one of the fastest ways to degrade the soft, clean water this species depends on.
How do Firehead Tetras behave — and what are good tank mates?
Firehead Tetras are completely peaceful and one of the most sociable community fish available. A school of eight or more will spend most of the day moving together in loose formation across the middle of the tank — the synchronized movement is a large part of their visual appeal. Schools smaller than eight tend to be skittish and spend more time hiding; larger schools of twelve or more produce the most confident, tightly grouped behaviour.
Their peaceful temperament makes them compatible with almost any non-aggressive, similarly-sized fish that shares their soft-water requirements. Classic companions include dwarf cichlids (Apistogramma spp.), corydoras catfish, other small soft-water tetras (cardinals, ember tetras, black neons), rasboras and otocinclus. Avoid fin-nippers, large cichlids, and hard-water species such as livebearers whose parameter requirements are incompatible.
For a full list of tested pairings, see Firehead Tetra tank mates.
How do you tell male from female Firehead Tetras?
Sexing Firehead Tetras is subtle but achievable in a healthy, mature school. Females are slightly deeper-bodied through the belly — the difference is most obvious when viewed from above — and tend to run marginally larger. Males are slimmer with a more streamlined body profile. Critically, both sexes carry identical colouration: the red head and caudal banding are present in males and females alike, so colour gives no clue.
The easiest time to sex the fish reliably is when females are carrying eggs, which rounds the abdomen noticeably. Outside of breeding condition, the differences are subtle enough that casual observation often cannot resolve them — which rarely matters for a community aquarium.
Can Firehead Tetras be bred in captivity?
Breeding is rated Hard and is considered a specialist project rather than a casual community-tank event. Like most Amazonian tetras, they scatter adhesive eggs among fine-leaved plants with no parental care, and the eggs and fry are extremely sensitive to water quality.
A dedicated breeding setup requires a small bare-bottom or java-moss tank of roughly 30–40 litres (8–10 gal), very soft slightly acidic water (pH 6.0–6.5, hardness below 4 dGH), near-darkness (eggs are light-sensitive), and a well-conditioned pair or trio pre-fed on daphnia and brine shrimp.
The adults will eat the eggs on contact; a fine mesh or layer of marbles on the bottom lets eggs fall out of reach. Remove adults after spawning. Eggs hatch in roughly 24 hours; fry are free-swimming within 4–5 days and need infusoria or commercial fry foods first, then baby brine shrimp. Water changes at the fry stage must be very small and gentle.
What diseases affect Firehead Tetras?
Common threats include ich (white spots — quarantine all new additions for two to four weeks), velvet (fine golden sheen, visible under a torch), fin rot (ragged edges driven by poor water quality — fix the water first), and neon tetra disease (pale body patches from a microsporidian with no reliable cure, making prevention the only strategy). The best prevention for all of them is the same: clean, stable, soft, warm water and a strict quarantine protocol for every new fish or plant.
Health note: medication dosing and specific disease diagnosis are beyond the scope of this care profile. For a sick fish, confirm the symptoms against a reputable veterinary or fish-health resource before treating, and remove any carbon from the filter before adding any medication to the tank.
How long do Firehead Tetras live?
In optimal conditions — soft, warm, clean water and a school of eight or more — Firehead Tetras live 3–5 years. The lower end is common in hard or alkaline water where chronic stress accumulates; the upper end is achievable in a mature planted tank that closely mirrors Rio Negro conditions. The colour of the school is your ongoing indicator: a school that stays vivid red is a school that is thriving.
Frequently asked questions
Is the Firehead Tetra the same as the Rummy-nose Tetra?
No — three species share the "Rummy-nose" look: Hemigrammus bleheri (Firehead Tetra), H. rhodostomus (true Rummy-nose) and Petitella georgiae (False Rummy-nose). H. bleheri is the one almost always sold in fish stores. It is distinguished by its red colouring extending well beyond the gill cover onto the body, and by a wider dark band into the caudal fin.
Why does my Firehead Tetra look pale?
Colour intensity is a direct read on fish stress and water quality. Pale heads usually mean the water is too warm, too hard, too alkaline, or the school is too small. Ensure temperature stays in the 24–28 °C range, pH 6.0–7.0, a school of at least eight, and a darkened substrate with some plant cover — colour will return within days.
What you need to keep a firehead tetra
The baseline is a heated, filtered 75 L+ tank: a reliable heater to hold 24–28 °C (75–82 °F), a gentle filter that won't batter a firehead tetra in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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