Should I buy it?
Neon Tetra
Paracheirodon innesi
Also known as: neon, paracheirodon innesi
The classic schooling tetra. Peaceful and stable in soft, settled water. Adding them to a tank under a month old loses half of any batch.
Neon Tetra tank mates · 40L tank size hub
peaceful · beginner care
Sources & confidencehigh · verified · beginner: excellent
Checked against several solid care sources that mostly agree. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: Established planted community tanks 60L+ where eight to ten neons can sit mid-water as a single moving shoal.
Avoid if: Your tank is brand new, your water is hard alkaline straight from the tap, or you keep cichlids large enough to gulp them.
Common mistakeBuying three neons for a splash of colour is the stocking error that fades within a week. A weak school stresses the fish, breaks the shoal, and invites the disease problems people then blame on bad luck. Start with at least six — preferably eight to ten — in an established tank. Token numbers are a display idea, not a neon ownership plan.
Top things that go wrong
- Group welfare — not a solo display fish. Plan at least **6** together for normal behaviour; smaller groups often mean stress, colour loss, or nipping depending on species.
- Shrimp & snails. Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
What most shops don't tell you
- 1.Neons are still sold into brand-new hard-water community tanks as if toughness were part of the stripe. Freshly set aquariums and alkaline tap swings are where neon disease stories begin. Established, softer, planted water with a quarantine habit for new bags is the boring advice that actually keeps a school. Pretty in the shop does not mean ready for your Tuesday water change.
- 2.Buying only three "for colour". Three neons read as stressed, washed-out fish that nip in the wrong tank.
- 3.Adding to a tank that is brand-new, uncycled, or otherwise unstable. The classic "neon die-off" path.
- 4.Keep six or more or they sulk and lose colour. First sign of trouble is one fish hanging back near the heater, not a whole-tank crash.
About this species
Neon tetras are small soft-water characins. The blue stripe catches under tank lighting. The red tail half only shows on settled fish, and stressed neons go grey.
- Ember Tetra45L min · same group, comparable tank size
- Beckford Pencilfish60L min · same group, similar adult size
- Black Neon Tetra60L min · same group, similar adult size
- Bloodfin tetra60L min · same group, similar adult size
- Cardinal Tetra60L min · same group, similar adult size
- Glowlight Tetra60L min · same group, similar adult size
- Green neon tetra60L min · same group, similar adult size
- Lemon Tetra60L min · same group, similar adult size
- Amano Shrimpalso beginner peaceful, similar tank size
- Assassin Snailalso beginner peaceful, similar tank size
- Beckford Pencilfishalso beginner peaceful, similar tank size
- Black Neon Tetraalso beginner peaceful, similar tank size
- Black phantom tetraalso beginner peaceful, similar tank size
- Bloodfin tetraalso beginner peaceful, similar tank size
- Adolfoi cory tank mateslists this fish as a safe and recommended mate
- Agassiz’s dwarf cichlid tank matesnames this fish as a conditional pairing — read the pair page conditions
- Amano Shrimp tank matesnames this fish as a conditional pairing — read the pair page conditions
- Assassin Snail tank matesnames this fish as a conditional pairing — read the pair page conditions
- Bamboo Shrimp tank mateslists this fish as a safe and recommended mate
- Black Neon Tetra tank mateslists this fish as a safe and recommended mate
- Black phantom tetra tank mateslists this fish among its recommended pairings
- Black ruby barb tank mateslists this fish as a safe and recommended mate
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease85
- Peacefulness90
- Community fit79
- Small-tank fit100
- Hardiness79
- Energy54
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Rough 90L+ layout: one calm centrepiece, 8–12 small tetras/rasboras, 6–8 corydoras-type bottom fish — verify every name in the pair checker before buying.
Safer directions include: Cherry Barb, Corydoras Catfish, Harlequin Rasbora.
Prioritise 6+ of Neon Tetra in 40L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.
Compatibility
Tank mates for Neon Tetra
Usually safer (engine GOOD): Cherry Barb, Corydoras Catfish, Harlequin Rasbora. Conditional (CAUTION — read the pair page before buying): Tiger Barb. Avoid (RISKY): Angelfish, Jack Dempsey, Oscar. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Neon Tetra + Cherry Barb
Behaviour and temperament
Neon Tetras only look like the postcard shoal when the group is large enough in soft, planted water. Six is the working floor; eight to ten is when the midwater stripe reads as one moving band. Below that, fish peel off as stressed individuals and the colour washes. They do not start fights with tank mates; a dark, clamped fish left behind the school is the one to isolate before the rest pay for it.
What sets them off
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper; stressed or crowded individuals can still test fins.
Predation: Not a predator toward similarly sized community fish; fry and dwarf shrimp are still fair game for most species.
Territory: Not strongly territorial, but still needs room so its working space does not overlap the next fish.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- Tight midwater school in soft, planted water; the blue-red stripe is the health meter.
- Six is the floor; eight to ten fills the midwater as a proper shoal.
- Stripe fading and fish hanging alone — classic neon disease or bad water; quarantine and test.
- School glued to the glass after a parameter swing.
- In-school chasing is normal; they do not start fights with tank mates.
- One fish dark, clamped, and left behind → remove it before the rest catch whatever it has.
- Never add new neons to a tank that just lost fish to disease without a quarantine plan.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
soft
Diet
omnivore
Neons have small mouths and lose weight quietly when they only get leftover flake from faster fish. Use crushed flake or true micro-pellets, and add baby brine shrimp or similarly tiny frozen food a few times a week. Feed where the school holds, not only at the surface rush. If the stripe stays bright but bellies look pinched, the display is ahead of the diet.
Shrimp & snails
Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
Schooling species — buy 6+ together. Smaller groups stress and lose colour.
- Hold 20 to 26 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6 to 7 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Schooling species. Buy 6 or more from the same tank on the same day before adding any centrepiece fish.
- Tank volume meets or exceeds 40L published minimum for adults.
- You can stock at least 6 individuals (group welfare).
- Heater can hold 20–26°C without cooking cooler-water tank mates.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 40L minimum tank needs a filter rated for at least 160L/hr turnover and a heater to hold 20–26°C reliably.
Plant suggestions
Neon Tetra does well in planted tanks. Plants compatible with 20–26°C and pH 6–7:
Research: verified · Confidence: high · 3 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Paracheirodon innesi
Supports: aquarium size, water chemistry, temperament and compatibility (primary care reference).
- FishBase. Paracheirodon innesi
Supports: taxonomy and wild maximum size — translate to tank stocking, not a target number.
- Wikipedia. Paracheirodon innesi
Supports: general species background and common-name orientation only.
Evidence notes
- Care numbers are cross-checked across the linked sources and biased toward the conservative end; compatibility reflects typical hobby experience, not a lab prediction. Method and full source policy: /methodology.
Featured compatibility checks
Curated pair pages for Neon Tetra. Each opens a full verdict — not just a list label.
Common questions about Neon Tetra
- How big do Neon Tetra get?
- Adult neons reach 3 to 4 cm. Small enough to be eaten by any fish over 8 cm with a wide mouth. Adult angelfish are the classic example.
- What size tank does Neon Tetra need?
- 40 L is the working minimum; 60 L is the recommended long-term size. Neons swim laterally, so the school needs length more than depth to settle into proper schooling.
- Are Neon Tetra aggressive?
- Neon Tetras only look like the postcard shoal when the group is large enough in soft, planted water. Six is the working floor; eight to ten is when the midwater stripe reads as one moving band. Below that, fish peel off as stressed individuals and the colour washes. They do not start fights with tank mates; a dark, clamped fish left behind the school is the one to isolate before the rest pay for it.
- Do Neon Tetra need to be kept in a group?
- Schooling species — buy 6+ together. Smaller groups stress and lose colour.
- What is the most common mistake with Neon Tetra?
- Buying three neons for a splash of colour is the stocking error that fades within a week. A weak school stresses the fish, breaks the shoal, and invites the disease problems people then blame on bad luck. Start with at least six — preferably eight to ten — in an established tank. Token numbers are a display idea, not a neon ownership plan.
- What fish can live with Neon Tetra?
- The Neon Tetra profile lists Cherry Barb, Corydoras Catfish, Harlequin Rasbora among its safer pairings (engine-checked GOOD). Tiger Barb is conditional (CAUTION): workable only with the specific conditions on its pair page. Avoid Angelfish, Jack Dempsey, Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.