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Black phantom tetra

Hyphessobrycon megalopterus

Also known as: phantom tetra, Phantom tetra

VerdictGOOD
Evidence: partially verified
Confidence: high
Beginner fit: good
peaceful
beginner care

Fishori provides conservative planning guidance, not guarantees.

Based on multiple reputable aquarium care sources with strong agreement. Use the numbers here as planning defaults — your room, water, and routine still shape real-world outcomes.

Min tank
80L
Adult (plan)
~3.5cm
Group min
6
Temp
2228°C

A 3.5 cm deep-bodied tetra in black or red morph. Males spread fins in display in competition. A school of eight or more produces constant passive display behaviour.

Best for

Planted community tanks 80L or more with soft to neutral water and a school of eight.

Avoid if

You keep fin-nippers or aggressive mid-water fish that prevent natural display behaviour.

Top things that go wrong

  1. 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.
  2. Shrimp & snails. Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.

Common mistakeSingle-morph purchase only. Red and black phantom tetras school together and the colour contrast between morphs is the visual effect.

What most shops don't tell you

  • 1.A single pair in 40L. Males harass without other phantoms to share line order.
  • 2.Mixed with nippy or fast surface fish, no mid-water escape structure.
  • 3.A mix of sexes settles the school. Two males alone in a small tank will bicker for line order. Fine-leaved plants and dim light pull the body colour out.

About this species

Black phantom tetras are dimorphic characins: males show a tall dorsal, females and mixed groups show a softer brown-grey body. A planted-tank species that stays peaceful in a school of six or more.

Similar fish
Same category, closest min-tank on file.
Related fish
Same care level & temperament, similar volume band.
Commonly paired with Black phantom tetra
Other species that list this fish as a safe or "best with" direction.

No reverse lookups on file yet.

Plan grid

Key limits are shown above; this section adds planning detail: pH band, swim level, bioload and activity, and the radar.

pH
5.5 – 7.5
Bioload (guide)
low
From Fishori trait map
Activity (guide)
medium
Flow medium · O₂ medium

Swim zones

Planning trait chart

Six indices for comparing species on paper before you spend.

Planning trait radar for this speciesBeginner easePeacefulnessCommunity fitSmall-tank fitHardinessEnergy
  • Beginner ease78
  • Peacefulness90
  • Community fit83
  • Small-tank fit100
  • Hardiness76
  • Energy54

Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.

Adult size (why it matters)
Plan stocking around 3.5 cm adult total length. Males, females, and individual strains can land a centimetre or two on either side, but that is the figure to budget swim space against, not the juvenile size in the shop tank.
Tank volume (what we mean)
80L is the planning floor for adult swimming space and bioload headroom. Long-term, a 98L+ tank lets adults use the full footprint without crowding the next species. Footprint, meaning length and front-to-back depth, matters as much as raw volume for active or territorial species.

Common setup sketches

Conservative patterns from Fishori fields — still run the pair checker for every species you add; sketches are not a stocking guarantee.

Beginner-style peaceful community (planning sketch)

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.

Safe directions on file include: Ember Tetra, Panda Corydoras, Glowlight Tetra.

Species-first shoal tank

Prioritise 6+ of Black phantom tetra in 80L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.

Tank mate intelligence

Use the "Often compatible" lists as a shortlist, not a stocking plan. Always run the pair tool and check the footprint of your actual tank first. Verify behaviour for Black phantom tetra against your own reading before you buy.

Safest directions

Pair-level compatibility with this fish as anchor.

Risky / situational

Read the blocking rule on each pair page before experimenting.

Avoid pairing

Do-not-stock combinations on conservative hobby rules.

Compare with

Run a real pair check: Black phantom tetra + Ember Tetra

If Black phantom tetra is the wrong pick — try instead
Safer directions on file, same conservative rules as the rest of the library. The best/avoid test lives in the card at the top of the page, not here.

Behaviour, temperament, and what to watch

Prose and lists come from the same record: read temperament first, then glass-level signals so you are not surprised after day three.

Temperament in the tank

Black phantom tetra is peaceful in mixed company.

Stress / aggression triggers on file

  • Sudden crowding
  • Poor water quality

Fin nipping: Not a habitual fin-nipper, but individuals can still test fins under stress or in a crowded tank.

Predation: Not a predator toward similarly-sized community fish. The usual community caveats about mouth size still apply for very small fry or shrimp.

Territory: Not strongly territorial, but still claims a working area in the tank. Give it room to settle without overlapping the next species' patch.

Planted tanks: excellenteasy plant ideas

In the glass: typical and warning signs

Typical behaviour
  • Moderate pacing — not hyperactive, not motionless.
  • Shoaling/schooling: most colour and confidence show when the group meets **6+**.
Stress signals
  • Clamped fins, gasping at the surface, hiding non-stop, or refusing food after the first week.
  • Rapid breathing when parameters swing — fix ammonia/nitrite first, then reassess mates.
Aggression signals
  • Low listed risk — still watch new introductions.
When to separate or rethink
  • Separate or rehome if injuries appear, one fish is pinned, or feeding becomes a daily chase.
  • If water is stable but behaviour worsens, reduce stocking or remove the highest-impact species first.

Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.

Care parameters: water, food, inverts, grouping

Chemistry and group rules sit here so you are not re-reading the same line from tank mate or temperament blocks. Swim level is in the plan grid above.

Water, feeding, inverts

Hardness

soft

Diet

omnivore

Mixed diet: a quality flake or pellet as the staple, with frozen or live foods two or three times a week.

Shrimp & snails

Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.

Grouping & social needs

Shoaling species. Buy 6 or more of one species together. Smaller schools sulk, lose colour, and redirect their schooling energy at whatever else is in the tank.

Egg scatterers and schoolers still spawn in stable tanks. Have a plan for the fry, or accept that the parents and tank mates will eat them in a community setup.

Before you buy — checklist
Tick mentally in the shop — every box should be true before you pay.
  • Hold 22 to 28 °C steadily on a real thermometer, not the dial on the heater.
  • Aim for pH 5.5 to 7.5 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 6 or more from the same tank on the same day before adding any centrepiece fish.
  • Tank volume meets or exceeds 80L published minimum for adults.
  • You can stock at least 6 individuals (group welfare).
  • Heater can hold 22–28°C without cooking cooler-water tank mates.
  • No known fin-nippers paired with long-finned fish unless you accept documented risk.

Explore and stocking hubs

Same library as the rest of Fishori: tank-mate index for this species, category peers, guides, and litre-based stocking lists where min tank on file is within the hub volume.

Plan with tools

Pair-level rules and multi-fish stocking use the same conservative engine — add this fish in the tank builder only after mates pass pair checks.

Filtration & heating

A 80L minimum tank needs a filter rated for at least 320L/hr turnover and a heater to hold 2228°C reliably.

Plant suggestions

Black phantom tetra does well in planted tanks. Plants compatible with 2228°C and pH 5.57.5:

Sources & evidence

Profile status: partially verified · Evidence tier: high · 3 linked source(s). Fishori does not fabricate citations.

Fishori uses conservative planning rules based on these sources.

Confidence is explained in the summary at the top of this page (same tier as here), not repeated below.

How Fishori evaluates compatibility (same logic as pair and tank tools).

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.
  • Fishori profiles work from typical aquarium trade sizes and hobby care norms. Specialist site checks and literature review for this species are not yet recorded here, so the ranges on this page are planning numbers rather than guarantees.