Should I buy it?
Green neon tetra
Paracheirodon simulans
Also known as: green neon, false neon
Smaller than regular neons at 2.5 cm with a longer green band. Requires soft acidic blackwater for full colour. Tougher than its label suggests.
Green neon tetra tank mates · 60L tank size hub
peaceful · intermediate care
Sources & confidencehigh · partially verified · beginner: caution
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: Blackwater nano and planted tanks 60L or more at pH 5.5–6.5 with a school of ten or more.
Avoid if: Hard tap water, bright non-tannin lighting, or tanks above 28 °C.
Common mistakeKeeping green neons in hard neutral tap is how keepers invent pale, undifferentiated fish that look nothing like the bag photo. Soften and stabilise water first. Eight or more in softish planted cover beats a hard bright handful every time — chemistry is not optional.
Top things that go wrong
- Group welfare — not a solo display fish. Plan at least **8** 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.Myth: green neon tetras thrive as a small handful in any hard bright community tank like hardy livebearers. Reality: they need soft, dimmer water and a real school — hard bright kits and token numbers wash them out and leave them hiding.
- 2.Kept in hard alkaline water. The colour and health fade inside a month.
- 3.Mixed with rambunctious or large fish in short tanks with no line-of-sight breaks.
- 4.Blackwater extracts or catappa leaves keep pH in the soft acidic range. Eight or more for the blue-green sheen to settle in the school.
About this species
- Beckford Pencilfish60L min · same group, comparable tank size
- Black Neon Tetra60L min · same group, comparable tank size
- Bloodfin tetra60L min · same group, comparable tank size
- Cardinal Tetra60L min · same group, comparable tank size
- Glowlight Tetra60L min · same group, comparable tank size
- Lemon Tetra60L min · same group, comparable tank size
- Silver Tip Tetra60L min · same group, comparable tank size
- X-ray tetra60L min · same group, comparable tank size
- Adolfoi coryalso intermediate peaceful, similar tank size
- Bamboo Shrimpalso intermediate peaceful, similar tank size
- Black ruby barbalso intermediate peaceful, similar tank size
- Brown / hockey-stick pencilfishalso intermediate peaceful, similar tank size
- Cardinal Tetraalso intermediate peaceful, similar tank size
- Celebes Rainbowfishalso intermediate peaceful, similar tank size
No reverse lookups listed yet.
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 ease38
- Peacefulness90
- Community fit91
- Small-tank fit100
- Hardiness54
- 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: Chili Rasbora, Dwarf Gourami, Ember Tetra.
Prioritise 8+ of Green neon tetra in 60L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.
Compatibility
Tank mates for Green neon tetra
Usually safer (engine GOOD): Chili Rasbora, Dwarf Gourami, Ember Tetra, Harlequin Rasbora, Neon Tetra. Conditional (CAUTION — read the pair page before buying): Betta, Corydoras Catfish, Pea Puffer, Serpae Tetra, Tiger Barb. Avoid (RISKY): African Cichlid, 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: Green neon tetra + Chili Rasbora
Behaviour and temperament
Green neon tetras are peaceful schoolers that stay calmer in groups of eight or more in soft water. They do not bully robust neighbours. Stress shows as fading, hiding, and losses when chemistry is hard or predators share the glass.
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
- Eight or more hold midwater as a green ribbon in soft planted water.
- Tight schooling after a fright is normal — give plants and length to reform.
- Faded colour in hard bright tanks usually means chemistry and light first.
- A scattered handful needs more of their own kind before a different staple.
- Low listed risk as aggressors.
- Angels, barbs, and large cichlids are the usual failure modes — not green-neon malice.
- Fix soft-water and school size before chasing mystery disease only.
- Remove predators and nippers at the first disappearance or tear.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
soft
Diet
omnivore
Green neon tetras are small soft-water omnivores that take micro-pellets, crushed flake, and fine frozen foods in a school of eight or more. Food that sinks past them too fast leaves them thin. Offer small portions in dimmer soft water, keep chemistry honest, and never treat hard bright tap as a neon-safe default.
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 8+ together. Smaller groups stress and lose colour.
- Hold 22 to 27 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 5 to 6.5 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 8 or more from the same tank on the same day before adding any centrepiece fish.
- Tank volume meets or exceeds 60L published minimum for adults.
- You can stock at least 8 individuals (group welfare).
- Heater can hold 22–27°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 60L minimum tank needs a filter rated for at least 240L/hr turnover and a heater to hold 22–27°C reliably.
Plant suggestions
Green neon tetra does well in planted tanks. Plants compatible with 22–27°C and pH 5–6.5:
Research: partially 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 simulans
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Paracheirodon simulans
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Paracheirodon simulans
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
Evidence notes
- The Seriously Fish profile for the binomial in this record was successfully reached as the primary aquarium reference.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- Wikipedia is only cited if the article URL returned OK. Use it for orientation, not as the only care sheet for an import.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
Common questions about Green neon tetra
- How big do Green neon tetra get?
- Green neon tetra adults reach about 2.5 cm. Shop fish look smaller; stock for the adult length.
- What size tank does Green neon tetra need?
- 60L is the planning floor for adult swimming space and bioload. A 73L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.
- Are Green neon tetra aggressive?
- Green neon tetras are peaceful schoolers that stay calmer in groups of eight or more in soft water. They do not bully robust neighbours. Stress shows as fading, hiding, and losses when chemistry is hard or predators share the glass.
- Do Green neon tetra need to be kept in a group?
- Schooling species — buy 8+ together. Smaller groups stress and lose colour.
- What is the most common mistake with Green neon tetra?
- Keeping green neons in hard neutral tap is how keepers invent pale, undifferentiated fish that look nothing like the bag photo. Soften and stabilise water first. Eight or more in softish planted cover beats a hard bright handful every time — chemistry is not optional.
- What fish can live with Green neon tetra?
- The Green neon tetra profile lists Chili Rasbora, Dwarf Gourami, Ember Tetra, Harlequin Rasbora among its safer pairings (engine-checked GOOD). Betta, Corydoras Catfish, Pea Puffer, Serpae Tetra are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid African Cichlid, Angelfish, Jack Dempsey, Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.