Photo: Manuel Gonzales (CC0) — via Wikimedia Commons
Purple Tetra (Hyphessobrycon metae)
A jewel-toned schooling tetra from the Orinoco basin that rewards soft, blackwater conditions with iridescent violet flanks.
Will it live with a Purple Tetra?
We compare each fish against your purple tetra on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- African Dwarf Frog✅ CompatiblePeaceful · 4 cm · Medium care · 22–26 °C (72–79 °F)
- Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Amapá Tetra✅ CompatiblePeaceful · 4 cm · Medium care · 24–27 °C (75–81 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Amapá Tetra in a shoal of 6+ or it gets stressed and nippy.
- Black Phantom Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful, and their water overlaps around 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Black Phantom Tetra in a shoal of 6+ or it gets stressed and nippy.
- Blue Danio✅ CompatiblePeaceful · 4 cm · Easy care · 21–26 °C (70–79 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Blue Danio in a shoal of 6+ or it gets stressed and nippy.
- Blue Emperor Tetra✅ CompatiblePeaceful · 4 cm · Medium 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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Blue Emperor Tetra in a shoal of 6+ or it gets stressed and nippy.
- Cardinal Tetra✅ CompatiblePeaceful · 4 cm · Medium care · 23–27 °C (73–81 °F)
- Both are peaceful, and their water overlaps around 23–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Cardinal Tetra in a shoal of 6+ or it gets stressed and nippy.
- Emperor Tetra✅ CompatiblePeaceful · 4 cm · Easy care · 23–27 °C (73–81 °F)
- Compatible on the things that matter: shared water near 23–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Emperor Tetra in a shoal of 6+ or it gets stressed and nippy.
- Flame Tetra✅ CompatiblePeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful, and their water overlaps around 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Flame Tetra in a shoal of 6+ or it gets stressed and nippy.
- Glowlight Tetra✅ CompatiblePeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Glowlight Tetra in a shoal of 6+ or it gets stressed and nippy.
- Gold Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 23–28 °C (73–82 °F)
- Both are peaceful, and their water overlaps around 23–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Gold Tetra in a shoal of 6+ or it gets stressed and nippy.
- Golden Dwarf Barb✅ CompatiblePeaceful · 4 cm · Easy care · 18–24 °C (64–75 °F)
- Compatible on the things that matter: shared water near 22–24 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Golden Dwarf Barb in a shoal of 6+ or it gets stressed and nippy.
- Jelly Bean Tetra✅ CompatiblePeaceful · 4 cm · Medium care · 20–26 °C (68–79 °F)
- Both are peaceful, and their water overlaps around 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Jelly Bean Tetra in a shoal of 10+ or it gets stressed and nippy.
- Lemon Tetra✅ CompatiblePeaceful · 4.5 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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Lemon Tetra in a shoal of 6+ or it gets stressed and nippy.
- Marbled Hatchetfish✅ CompatiblePeaceful · 4 cm · Medium care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Marbled Hatchetfish in a shoal of 6+ or it gets stressed and nippy.
- Otocinclus✅ CompatiblePeaceful · 4 cm · Medium care · 21–26 °C (70–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Otocinclus in a shoal of 6+ or it gets stressed and nippy.
- Phoenix Tetra✅ CompatiblePeaceful · 4 cm · Easy care · 23–28 °C (73–82 °F)
- Both are peaceful, and their water overlaps around 23–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Phoenix Tetra in a shoal of 8+ or it gets stressed and nippy.
- Rainbow Emperor Tetra✅ CompatibleSemi-aggressive · 3.6 cm · Medium care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Rainbow Emperor Tetra in a shoal of 8+ or it gets stressed and nippy.
- Red Phantom Tetra✅ CompatiblePeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Red Phantom Tetra in a shoal of 8+ or it gets stressed and nippy.
- Rosy Tetra✅ CompatiblePeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Rosy Tetra in a shoal of 6+ or it gets stressed and nippy.
- Sparkling Gourami✅ CompatiblePeaceful · 4 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Strawberry Betta✅ CompatiblePeaceful · 4 cm · Medium care · 22–27 °C (72–81 °F)
- Compatible on the things that matter: shared water near 22–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Threadfin Rainbowfish✅ CompatiblePeaceful · 4 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.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Threadfin Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Tiger Otocinclus✅ CompatiblePeaceful · 4 cm · Medium care · 22–27 °C (72–81 °F)
- Both are peaceful, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Tiger Otocinclus in a shoal of 6+ or it gets stressed and nippy.
- Yellow Phantom Tetra✅ CompatiblePeaceful · 4 cm · Easy care · 23–27 °C (73–81 °F)
- Both are peaceful, and their water overlaps around 23–26 °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 Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Yellow Phantom Tetra in a shoal of 6+ or it gets stressed and nippy.
- Black Darter Tetra⚠️ With cautionSemi-aggressive · 4 cm · Hard care · 21–28 °C (70–82 °F)
- Black Darter Tetra and Purple Tetra are close in size, but the semi-aggressive one tends to dominate — add purple tetra in a group to spread the pressure.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Blue Turbo Snail⚠️ With cautionPeaceful · 5 cm · Medium care · 25–30 °C (77–86 °F)
- Different pH ranges (5.8–6.8 vs 7.5–8.5); doable if you sit in the shared band, but not ideal long-term.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Cherry Shrimp⚠️ With cautionPeaceful · 3 cm · Easy care · 18–28 °C (64–82 °F)
- Adult Cherry Shrimp might survive with Purple Tetra, but expect the young to be eaten — plant heavily.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Cherry Shrimp in a shoal of 10+ or it gets stressed and nippy.
- Endler's Livebearer⚠️ With cautionPeaceful · 3 cm · Easy care · 22–28 °C (72–82 °F)
- Different pH ranges (5.8–6.8 vs 7–8.5); doable if you sit in the shared band, but not ideal long-term.
- Water hardness preferences differ (Purple Tetra 1–8 vs Endler's Livebearer 10–25 dGH).
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Endler's Livebearer in a shoal of 6+ or it gets stressed and nippy.
- Ghost Shrimp⚠️ With cautionPeaceful · 4 cm · Easy care · 18–28 °C (64–82 °F)
- Adult Ghost Shrimp might survive with Purple Tetra, but expect the young to be eaten — plant heavily.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Ghost Shrimp 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 is semi-aggressive and may chase or nip the smaller Purple Tetra — plant heavily and break up sight lines.
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Purple 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.
- Japanese Trapdoor Snail⚠️ With cautionPeaceful · 5 cm · Easy care · 10–28 °C (50–82 °F)
- Different pH ranges (5.8–6.8 vs 7–8); doable if you sit in the shared band, but not ideal long-term.
- Keep Purple 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 Purple 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.
- Mystery Snail⚠️ With cautionPeaceful · 5 cm · Easy care · 20–28 °C (68–82 °F)
- Different pH ranges (5.8–6.8 vs 7–8); doable if you sit in the shared band, but not ideal long-term.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Rummy Nose Rasbora⚠️ With cautionPeaceful · 4 cm · Medium care · 20–26 °C (68–79 °F)
- Different pH ranges (5.8–6.8 vs 7–8); doable if you sit in the shared band, but not ideal long-term.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Rummy Nose Rasbora in a shoal of 8+ or it gets stressed and nippy.
- Serpae Tetra⚠️ With cautionSemi-aggressive · 4 cm · Easy care · 23–28 °C (73–82 °F)
- Expect Serpae Tetra to harass Purple Tetra at times; give dense cover and watch them at feeding.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Keep Serpae 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)
- Silvertip Tetra and Purple Tetra are close in size, but the semi-aggressive one tends to dominate — add purple tetra in a group to spread the pressure.
- Keep Purple 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 Purple Tetra — plant heavily and break up sight lines.
- Keep Purple 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)
- Striped Red-Eye Puffer and Purple Tetra are close in size, but the aggressive one tends to dominate — add purple tetra in a group to spread the pressure.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Tiger Badis⚠️ With cautionSemi-aggressive · 4 cm · Medium care · 22–24 °C (72–75 °F)
- Tiger Badis and Purple Tetra are close in size, but the semi-aggressive one tends to dominate — add purple tetra in a group to spread the pressure.
- Keep Purple 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 Purple Tetra are close in size, but the aggressive one tends to dominate — add purple tetra in a group to spread the pressure.
- Keep Purple 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)
- Purple Tetra is bite-sized to a 250 cm predatory alligator gar — it will be eaten.
- Alligator Gar is aggressive and may chase or nip the smaller Purple Tetra — plant heavily and break up sight lines.
- Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Keep Purple 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 4 cm Purple Tetra whole.
- Clown Knifefish clearly outsizes Purple Tetra and is aggressive; risky unless the tank is big and well-planted.
- Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Keep Purple 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 4 cm Purple Tetra whole.
- Fire Eel clearly outsizes Purple Tetra and is semi-aggressive; risky unless the tank is big and well-planted.
- Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Keep Purple 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)
- Size gap is too large (90 vs 4 cm): Koi will treat Purple Tetra as food.
- Water hardness preferences differ (Purple Tetra 1–8 vs Koi 9–18 dGH).
- Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Keep Purple 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)
- Size gap is too large (120 vs 4 cm): Redtail Catfish will treat Purple Tetra as food.
- Expect Redtail Catfish to harass Purple Tetra at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Keep Purple 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 4 cm): Spotted Gar will treat Purple Tetra as food.
- Expect Spotted Gar to harass Purple 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 Purple 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)
- Size gap is too large (300 vs 4 cm): Wels Catfish will treat Purple Tetra as food.
- Wels Catfish clearly outsizes Purple 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 Purple 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 4 cm): Wolf Cichlid will treat Purple Tetra as food.
- Different pH ranges (5.8–6.8 vs 7–8); doable if you sit in the shared band, but not ideal long-term.
- Wolf Cichlid clearly outsizes Purple 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 Purple 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.
Purple Tetra care specs
- Care level
- Medium
- Breeding
- Hard
- Max size
- 4 cm (1.6 in)
- Min tank size
- 60 L (15.9 gal)
- Temperature
- 22–26 °C (72–79 °F)
- pH
- 5.8–6.8
- Hardness
- 1–8 dGH
- Lifespan
- 3–5 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 8+ (shoaling)
- Family
- Characidae
- Origin
- South America — Río Meta and middle Orinoco basin, Colombia and Venezuela
What is a Purple Tetra?
The Purple Tetra (Hyphessobrycon metae), also called the Rio Meta tetra or Meta tetra, is a small blackwater characin from the Río Meta and middle Orinoco watershed in Colombia and Venezuela. Reaching just 4 cm (1.5 in), it is compact even by tetra standards — but under soft, acidic water the flanks shift from plain silver to a deep iridescent violet-purple, which is why it has a devoted following among South American biotope and planted-tank keepers. It is rated medium care level not because it is fragile, but because it is water-chemistry sensitive: get the chemistry right and it is rewarding; keep it in hard tap water and it will rarely colour up or thrive.
Where do Purple Tetras come from?
Wild Purple Tetras inhabit the Río Meta basin and connecting tributaries of the middle Orinoco in Colombia and Venezuela — a network of rivers draining the Llanos and Andean foothills into one of South America’s great drainages. These are classic blackwater environments: tannin-stained from decomposing leaf litter, extremely soft (as low as 1 dGH), and acidic, with pH values that can drop well below 6.0 in isolated forest streams.
The water is warm, slow-moving and tannin-stained, with a substrate of fine sand, root tangles and accumulated leaf litter. Soft, dark, warm and gentle-flowing: replicate those conditions and the fish looks its best.
What size tank does a Purple Tetra need?
The minimum practical tank size is 60 litres (16 gal). This reflects both the swimming needs of a species that is always on the move in mid-water and the minimum group size of eight individuals. A longer, shallower footprint — 80 cm (31 in) or more in length — is preferable to a tall, narrow tank, as it gives the school room to form and turn cohesively.
Larger groups in 90–120 L (24–32 gal) tanks are noticeably calmer and more colourful. Dense planting, driftwood and Indian almond leaves or oak leaves reinforce the biotope feel and naturally help soften and acidify the water.
What water parameters does the Purple Tetra need?
- Temperature: 22–26 °C (72–79 °F) — the cooler end suits long-term maintenance; the warmer end can encourage breeding.
- pH: 5.8–6.8. Best colouration and health appear around 6.0–6.5. The fish can survive to 6.8 but breeding is unlikely above 6.5.
- Hardness: 1–8 dGH. This is a soft-water species; anything above 10 dGH suppresses colour and long-term health.
Most tap water needs treatment. RO water blended with a small proportion of mineral-rich tap water is the most controllable approach; alternatively, peat filtration or aged driftwood will naturally soften and acidify over time. Always test hardness with a dedicated kit — pH alone does not capture the full picture. Keep filtration gentle: two to three times tank volume per hour, with a canister throttled back or a sponge filter, suits this low-flow species.
What do Purple Tetras eat?
Purple Tetras are omnivores but lean toward invertebrate protein in the wild. In the aquarium they accept a broad diet:
- Staple: quality micro-pellets or fine-ground flake sized to their small mouths (4 cm / 1.5 in fish need small food).
- Live and frozen: baby brine shrimp, micro-worms, daphnia and finely chopped bloodworm are eagerly taken and noticeably improve condition and colour.
- Occasional plant matter: a small algae-based wafer or blanched spinach rounds out the diet.
Feed small amounts once or twice daily — what they consume in two to three minutes. Overfeeding quickly degrades water quality in the soft, lightly buffered conditions they prefer. Rotating live and frozen foods through the week is particularly worthwhile if you intend to breed them, as it brings females into spawning condition more reliably than dry food alone.
Are Purple Tetras peaceful — and what fish can live with them?
Purple Tetras are reliably peaceful and almost never fin-nip when kept in a school of eight or more. The risk of nipping rises sharply in groups below six, or when the fish are kept with long-finned slow-moving species — a consequence of stress and crowding rather than inherent aggression.
Good companions share the same chemistry needs: other small South American characins (cardinal, ember, rummy-nose tetras), soft-water Apistogramma dwarf cichlids, small Corydoras and Otocinclus. Avoid large or boisterous species, and avoid any fish that needs harder, more alkaline water — the chemistry compromise will always disadvantage the Purple Tetra.
For a filterable list of vetted pairings, see Purple Tetra tank mates.
How do you tell a male from a female Purple Tetra?
Sexual dimorphism in this species is moderate and most visible in mature, well-conditioned fish.
- Males are slimmer in profile, with a slightly flatter ventral line, and in peak condition show marginally more intense violet-purple iridescence along the flanks.
- Females become noticeably fuller-bodied and rounder in the belly when ripe with eggs, making the sexes straightforward to distinguish in a group prior to spawning.
Juveniles and underconditioned adults are harder to distinguish; several weeks of live or frozen foods will bring mature females into visible spawning condition.
How do Purple Tetras breed?
Breeding the Purple Tetra is rated hard and requires deliberate setup rather than accidental spawning in a community tank.
A dedicated breeding tank of 20–30 L (5–8 gal) should be set up with very soft, acidic water — target pH 5.8–6.2 and hardness below 3 dGH — at the warmer end of the temperature range (25–26 °C / 77–79 °F). Use a thin layer of fine-leaved plants (Java moss works well) or spawning mop as an egg trap, and keep lighting dim. Like most egg-scattering tetras, Purple Tetras will eat their own eggs immediately, so the adults should be removed as soon as spawning is observed.
Condition a selected pair on live and frozen foods for two to three weeks before moving them to the breeding tank. Eggs hatch in about 24–36 hours and fry become free-swimming a few days later; feed infusoria or liquid fry food first, then baby brine shrimp as they grow. Keep the fry tank very clean — ammonia spikes quickly in a small, soft-water volume.
What diseases are common in Purple Tetras?
The Purple Tetra is not intrinsically disease-prone, but its narrow water-chemistry requirements mean that stress from incorrect parameters is the leading gateway to illness.
- White spot (ich): the classic small-tetra complaint, usually triggered by temperature instability or the stress of new arrival. Prevention is a stable heater and a quarantine period for all new fish.
- Velvet (Oodinium): appears as a fine gold or rust dust on the flanks; more common in very soft, warm, low-flow tanks. Good observation habits catch it early.
- Fin rot and bacterial infections: most commonly traced to water quality — elevated ammonia or nitrite in a soft, poorly buffered tank degrades rapidly. Weekly water changes of 20–25 % and careful feeding discipline are the primary prevention.
- Internal parasites: fish imported from the wild may carry internal worms. A quarantine tank for all new arrivals is the single most effective defence.
Health note: medication dosing and disease diagnosis are outside the scope of a care profile. If you suspect illness, confirm symptoms against a veterinary or specialist fish-health resource before treating. Note that many medications are poorly tolerated in the very soft, acidic water Purple Tetras require — always check compatibility.
How long do Purple Tetras live?
A well-kept Purple Tetra lives 3–5 years. Fish maintained in hard or alkaline water rarely reach that upper figure; those in a mature, soft-water, well-planted tank with a stable temperature and varied diet regularly do. Get the water right and a shoal will deliver years of shimmering mid-water activity and the violet iridescence that makes the setup effort worthwhile.
Frequently asked questions
Why does the Purple Tetra need such low pH water?
In the wild it inhabits blackwater streams in the Orinoco basin where pH can drop below 5.5. While it survives at 6.8, its best colour, health and willingness to breed appear in soft, acidic water around pH 6.0. Hard or alkaline tap water should be conditioned with peat or RO before use.
How many Purple Tetras should I keep together?
A minimum group of eight is strongly recommended. In smaller numbers they become nervous, lose colour and may nip. A group of ten or more in a well-planted tank brings out natural schooling behaviour and the full iridescent display.
What you need to keep a purple tetra
The baseline is a heated, filtered 60 L+ tank: a reliable heater to hold 22–26 °C (72–79 °F), a gentle filter that won't batter a purple tetra in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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