Photo: Waugsberg (CC BY 2.5) — via Wikimedia Commons
Lemon Tetra (Hyphessobrycon pulchripinnis)
A sparkling, translucent yellow tetra with a vivid lemon-and-black dorsal fin — one of the easiest and most rewarding shoalers for a planted community tank.
Will it live with a Lemon Tetra?
We compare each fish against your lemon tetra on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Amano Shrimp✅ CompatiblePeaceful · 5 cm · Easy care · 18–28 °C (64–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Lemon Tetra 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 23–28 °C — no size, zone or temperament conflicts.
- Keep Lemon 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)
- Compatible on the things that matter: shared water near 23–27 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Lemon 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.
- Black Phantom Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 22–28 °C (72–82 °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 Lemon Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Black Phantom Tetra in a shoal of 6+ or it gets stressed and nippy.
- Blue Turbo Snail✅ CompatiblePeaceful · 5 cm · Medium 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.
- Keep Lemon 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 23–25 °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 Lemon 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)
- Compatible on the things that matter: shared water near 23–27 °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 Lemon 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; 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 Lemon 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)
- 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 Lemon 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 Lemon 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, 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 Lemon 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 Lemon 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.
- Gold Tetra✅ CompatiblePeaceful · 4.5 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.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Lemon Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Gold Tetra 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; 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 Lemon 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; 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 Lemon 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)
- 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 Lemon 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)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Lemon 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Lemon 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Lemon 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 Lemon 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)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Lemon 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Lemon 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.
- X-ray Tetra✅ CompatiblePeaceful · 4.5 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 Lemon Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep X-ray Tetra in a shoal of 6+ or it gets stressed and nippy.
- Yellow Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 20–25 °C (68–77 °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 Lemon Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Yellow 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 Lemon Tetra are close in size, but the semi-aggressive one tends to dominate — add lemon 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 Lemon 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 Lemon Tetra at times; give dense cover and watch them at feeding.
- Keep Lemon 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.
- 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 Lemon Tetra — plant heavily and break up sight lines.
- Keep Lemon 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 Lemon 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)
- Eastern Betta is semi-aggressive and may chase or nip the smaller Lemon Tetra — plant heavily and break up sight lines.
- Keep Lemon Tetra 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)
- Lemon Tetra may eat Ghost Shrimp or pick off its shrimplets — a densely planted tank with moss gives them a fighting chance.
- Keep Lemon Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Ghost Shrimp 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 Lemon Tetra — plant heavily and break up sight lines.
- Keep Lemon 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)
- Humpbacked Tetra and Lemon Tetra are close in size, but the semi-aggressive one tends to dominate — add lemon 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 Lemon 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 Lemon 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)
- Expect Odessa Barb to harass Lemon Tetra at times; give dense cover and watch them at feeding.
- Keep Lemon 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.
- Peaceful Betta⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
- Peaceful Betta and Lemon Tetra are close in size, but the semi-aggressive one tends to dominate — add lemon tetra in a group to spread the pressure.
- Keep Lemon 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 is semi-aggressive and may chase or nip the smaller Lemon Tetra — plant heavily and break up sight lines.
- Keep Lemon 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.
- Smaragd Betta⚠️ With cautionAggressive · 6 cm · Medium care · 23–28 °C (73–82 °F)
- Smaragd Betta is aggressive and may chase or nip the smaller Lemon Tetra — plant heavily and break up sight lines.
- Keep Lemon 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)
- Expect Spotfin Betta to harass Lemon Tetra at times; give dense cover and watch them at feeding.
- Keep Lemon 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 Lemon Tetra are close in size, but the aggressive one tends to dominate — add lemon tetra in a group to spread the pressure.
- Keep Lemon 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)
- Expect Wine Red Betta to harass Lemon Tetra at times; give dense cover and watch them at feeding.
- Keep Lemon 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 4.5 cm Lemon Tetra whole.
- Alligator Gar clearly outsizes Lemon 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 Lemon 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 4.5 cm Lemon Tetra whole.
- Clown Knifefish clearly outsizes Lemon 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 Lemon 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)
- Fire Eel (100 cm) is big enough to swallow the 4.5 cm Lemon Tetra whole.
- Fire Eel is semi-aggressive and may chase or nip the smaller Lemon Tetra — plant heavily and break up sight lines.
- Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Keep Lemon 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 4.5 cm Lemon Tetra whole.
- Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Keep Lemon 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 4.5 cm Lemon Tetra whole.
- Redtail Catfish is aggressive and may chase or nip the smaller Lemon 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 Lemon 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 4.5 cm Lemon Tetra whole.
- Spotted Gar is aggressive and may chase or nip the smaller Lemon 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 Lemon 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 4.5 cm Lemon Tetra whole.
- Wels Catfish is aggressive and may chase or nip the smaller Lemon 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 Lemon 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)
- Size gap is too large (72 vs 4.5 cm): Wolf Cichlid will treat Lemon Tetra as food.
- Wolf Cichlid is aggressive and may chase or nip the smaller Lemon 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 Lemon 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.
Lemon Tetra care specs
- Care level
- Easy
- Breeding
- Medium
- Max size
- 4.5 cm (1.8 in)
- Min tank size
- 60 L (15.9 gal)
- Temperature
- 23–28 °C (73–82 °F)
- pH
- 6–7.5
- Hardness
- 3–15 dGH
- Lifespan
- 3–5 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 6+ (shoaling)
- Family
- Characidae
- Origin
- South America — Tapajós and lower Amazon basin, Brazil
What is a Lemon Tetra?
The lemon tetra (Hyphessobrycon pulchripinnis) is a small Amazonian characid that punches well above its size for visual impact. Adults reach just 4.5 cm (about 1.8 in), yet the translucent yellow body, vivid lemon-and-black dorsal fin, and jewel-bright red iris create a distinctive look that stands out in any planted tank. Under good aquarium lighting, a tight shoal moving through dark green plants looks almost luminescent.
Classified as easy to keep, lemon tetras have earned a reputation as a model community fish. They are peaceful, undemanding about water conditions within a reasonable range, accept most commercially available foods, and adapt well to a wide variety of planted-tank setups. Whether you are setting up your first community aquarium or adding a shoaling species to a mature display tank, the lemon tetra is a reliable, rewarding choice.
Where do Lemon Tetras come from?
Lemon tetras are native to South America, specifically the Tapajós River and the lower Amazon basin in Brazil. In the wild they inhabit calm, slow-moving tributaries, floodplain pools, and forest streams where the water is warm, soft, and often tea-coloured from tannins released by decaying leaf litter and wood.
That origin is worth keeping in mind when setting up their tank. Lemon tetras evolved in water that is naturally low in mineral hardness and slightly acidic, filtered through dense riparian vegetation. They are more adaptable than many Amazonian tetras — neutral tap water suits them in most regions — but the closer you can mirror their natural environment, the better their colour, behaviour, and long-term health will be.
What size tank does a Lemon Tetra need?
The practical minimum is 60 litres (about 16 gallons), and that figure assumes a shoal of six, which is the smallest group that keeps these fish calm and confident. A longer tank footprint (60 cm / 24 in or more) serves them better than a tall one; lemon tetras are middle-column swimmers and spend most of their time cruising horizontally through open water and plant edges.
Aim for moderate, gentle flow — a steady current from a hang-on-back or canister filter suits them well, but strong turbulence is unnecessary and uncomfortable for such a small fish. A well-planted setup with some open swimming space, a dark substrate, and floating plants or a dimmed light area will bring out the deepest yellow tones. Dense planting also gives any slightly skittish individual a place to retreat, which reduces stress across the whole group.
What water parameters do Lemon Tetras need?
- Temperature: 23–28 °C (73–82 °F). Aim for the middle of that range — around 25–26 °C — for everyday keeping.
- pH: 6.0–7.5. Slightly acidic to neutral water is ideal; hard, alkaline water above pH 7.5 dulls their colour over time.
- Hardness: 3–15 dGH (soft to moderately hard). They are more tolerant of harder water than many Amazonian tetras, but very hard water should be avoided.
As with most small tetras, stability matters more than chasing exact numbers. Cycle your tank fully before adding fish, perform weekly water changes of around 25–30 %, and avoid sudden temperature swings. A lemon tetra kept in steady, clean, moderately soft water will hold colour and condition for its full lifespan far better than one kept in chemically perfect but fluctuating water.
What do Lemon Tetras eat?
Lemon tetras are omnivores with an unsophisticated appetite — which is part of what makes them such an easy species to keep. A quality micro-pellet or small-grade flake food forms a solid staple. Supplement this two or three times a week with protein-rich live or frozen foods: daphnia, baby brine shrimp, micro worms, and finely chopped bloodworm are all accepted readily.
Variety makes a visible difference. Fish fed only dry flake tend to be paler and less active than those receiving a rotation of live and frozen foods. Feed small amounts once or twice daily — only as much as the fish consume within two minutes — and skip a feeding once a week to prevent overfeeding and the water-quality issues that follow. Their small mouths mean food particle size matters; choose appropriately sized offerings so every fish in the shoal gets access.
Are Lemon Tetras aggressive — and what fish can live with them?
Lemon tetras are peaceful and are among the safer community choices for a mixed planted tank. They spend most of their time in the middle water column, schooling actively among themselves rather than pestering other species. However, there is one meaningful caveat: in groups smaller than six, individuals can become mildly nippy toward long-finned tankmates such as bettas or angelfish. The solution is straightforward — keep six or more, and the fin-nipping tendency disappears as the shoal directs its energy inward.
Good tankmates share similar water requirements and a non-aggressive disposition. Corydoras catfish, otocinclus, small rasboras, other peaceful tetras, and dwarf cichlids such as apistogramma are all classic companions. Avoid fish large enough to swallow a 4.5 cm tetra, or fin-nipping species like tiger barbs, which will out-nippy even a lemon tetra.
For a full list of tested compatible and incompatible species, see Lemon Tetra tank mates.
How do you tell male and female Lemon Tetras apart?
Sexing lemon tetras is relatively straightforward in conditioned adults. Females are noticeably rounder and deeper-bodied when carrying eggs — look at the belly profile from above or from the side. Males have a sharper, crisper black edge along the anal fin; in females this edge is softer and less defined.
The colour difference between sexes is subtle and not a reliable indicator on its own. The body shape and anal-fin edge remain the most practical ways to identify sex in a group. Conditioning fish on a varied diet that includes live or frozen foods typically makes the difference between males and females more obvious.
How do Lemon Tetras breed?
Breeding lemon tetras is achievable for an intermediate keeper but requires some preparation, which is why we rate it medium difficulty. They are egg scatterers with no parental care — the adults will readily consume their own eggs if given the chance.
Set up a dedicated breeding tank of around 20–30 litres (5–8 gal), filled with soft, slightly acidic water (pH 6.0–6.5, hardness toward the lower end of their range, temperature around 26–27 °C / 79–81 °F). Fine-leaved plants or a spawning mop give the eggs somewhere to fall and hide. Condition a pair separately on live and frozen foods for one to two weeks before introducing them together.
Spawning typically happens in the morning, with the pair scattering adhesive eggs among plants. Remove the adults after spawning to prevent egg predation. Eggs hatch in roughly 24–30 hours; fry are free-swimming a few days later and require infusoria or commercial fry food initially, graduating to baby brine shrimp as they grow. Keep the breeding tank dim — eggs and young fry are sensitive to strong light.
What are common Lemon Tetra diseases?
Lemon tetras are hardy for their size, but they are susceptible to the diseases that affect most small community fish when kept in suboptimal conditions.
Ich (Ichthyophthirius multifiliis) presents as small white spots on the body and fins, accompanied by flashing and scratching against decor. It is almost always introduced via new fish or plants and is most likely to take hold when fish are stressed by cold temperatures or poor water quality.
Fin rot appears as ragged, receding fin edges and is typically a consequence of bacterial infection following stress, injury, or chronically poor water conditions. Improving water quality is the first and most important step.
Neon tetra disease (caused by Pleistophora hyphessobryconis) can affect other small tetras including lemon tetras, presenting as faded patches, curved spine, and wasting. There is no effective treatment; removing affected fish promptly is important to prevent spread.
Velvet (a fine gold or rust-coloured dusting on the body, caused by Oodinium) is another possibility, particularly in weakened fish.
Prevention follows a common pattern: quarantine all new fish for two to four weeks before introducing them to the display tank, maintain stable water parameters with regular partial water changes, and avoid sudden temperature drops. A clean, well-oxygenated, cycled tank removes most of the conditions that allow disease to take hold.
Health note: disease diagnosis and medication choices are beyond the scope of a care profile. Confirm symptoms against a reputable veterinary or fish-health source before reaching for any treatment, and always follow product instructions carefully.
How long do Lemon Tetras live?
A well-kept lemon tetra lives 3–5 years. The lower end of that range tends to reflect fish kept in marginal conditions — incorrect temperature, poor water quality, or chronic stress from inadequate group size. Fish maintained in soft-to-neutral, stable water at the right temperature, fed a varied diet, and kept in a shoal of six or more routinely reach four to five years.
Because lemon tetras are small and inexpensive, they are sometimes treated as disposable. In a thoughtfully set-up planted community tank, however, a mature shoal develops a confident, coordinated schooling behaviour that improves with age — making the investment in good long-term care more than worthwhile.
Frequently asked questions
How many lemon tetras should I keep together?
Keep a minimum of six, and eight or more is better. In small groups of fewer than six they can become slightly nippy toward long-finned tankmates. A larger shoal channels that energy into schooling behaviour and shows off their translucent yellow colouration at its best.
What water conditions do lemon tetras need?
They come from soft, slightly acidic Amazonian water and thrive in pH 6.0–7.5 with soft-to-moderately-hard water (3–15 dGH) and temperatures of 23–28 °C. They adapt to neutral tap water in many regions, but avoid hard, alkaline water — it tends to dull their colour and shorten their lifespan.
What you need to keep a lemon tetra
The baseline is a heated, filtered 60 L+ tank: a reliable heater to hold 23–28 °C (73–82 °F), a gentle filter that won't batter a lemon tetra in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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