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Compatibility Report

Can Cardinal Tetra Live With Clown Loach?

GuideMyTank compatibility analysis for Cardinal Tetra and Clown Loach.

Planning verdict

caution

Conditional

Only plan this pair if every listed condition can be met, and have a separation plan if stress or aggression appears.

Data confidence
high
Assessment source
Structured data model
Data completeness
100%

Blocking risks

No automatic safety blocker was found.

Conditions and cautions

  • One species requires a significantly larger aquarium.
  • A species needing stable water has only a narrow pH, GH, or KH overlap.
  • Specialist tank style requirements need careful matching.

Supporting factors

  • Temperature ranges overlap well.
  • pH requirements overlap well.
  • Species have similar temperament.
  • Both species have compatible schooling or group behavior.
  • No predation risk detected.
Cardinal Tetra profileClown Loach profileMethodology and limitations

Why This Pair Received Its Verdict

Cardinal Tetra and Clown Loach receive a conditional verdict from the current structured assessment. Cardinal Tetra is recorded as peaceful with an aggression level of 1/10; Clown Loach is recorded as peaceful with an aggression level of 2/10. The recommendation is based on the combined water, space, behavior, grouping, and predation checks below rather than on species names alone.

  • Temperature ranges overlap well.
  • pH requirements overlap well.
  • Species have similar temperament.
  • Both species have compatible schooling or group behavior.

Helpful Links

Use the Compatibility CheckerRead the Compatibility Disclaimer

Water Parameter Overlap

Cardinal Tetra has a recorded temperature range of 73–84°F and pH range of 5–7. Clown Loach is recorded at 75–86°F and pH 6–7.5. Their shared planning window is 75–84°F for temperature and 6–7 for pH. A shared aquarium must stay inside the overlap rather than merely touching each species’ outer tolerance.

Aquarium Space and Adult Size

Clown Loach sets the larger listed base aquarium requirement at 100 gallons; the other listed minimum is 20 gallons. Clown Loach is the larger adult by the recorded maximum, reaching 12 inches, compared with 2 inches. These figures are starting constraints, not a stocking-capacity calculation, because the complete group sizes and bioload still matter.

Behavior and Social Requirements

Cardinal Tetra is a calm species associated with the mid zone and moderate flow. Clown Loach is active, uses the bottom zone, and has a moderate flow preference. Cardinal Tetra should be planned as a group of at least 8, while clown loach should be planned as a group of at least 6. The aquarium must support both social structures without forcing either species into insufficient space.

Husbandry Fit

Cardinal Tetra is recorded as a omnivore with intermediate care, while Clown Loach is a omnivore with advanced care. Their listed preferred tank styles are blackwater and planted. Feeding access, cover, open swimming room, filtration, and observation should be planned around the more demanding requirement rather than averaged between the two species.

What Would Change the Decision?

Use these pair-specific boundaries before treating the verdict as an acceptable stocking plan.

  • Do not proceed unless one stable temperature and pH range can be maintained for both Cardinal Tetra and Clown Loach; acclimation does not correct an incompatible long-term range.
  • Treat size, predation, and fin-damage warnings as stop conditions. Extra plants cannot reliably make an unsafe predator-to-prey or fin-target pairing safe.
  • Use broken sight lines and multiple retreats, then separate the pair if either species shows persistent chasing, hiding, clamped fins, or loss of feeding access.
  • Recalculate space using the full adult group sizes—not one specimen of each species—and reject the plan if either species must be understocked socially to fit.
  • Prepare a cycled backup or separation option before introduction; individual behavior can be less predictable than species-level records.

Aquarium Planning Checklist

  • Keep temperature within 75–84°F.
  • Keep pH within 6–7.
  • Use at least the larger 100-gallon base requirement before accounting for the complete stocking plan.
  • Cardinal Tetra should be planned as a group of at least 8; clown loach should be planned as a group of at least 6.
  • Provide a separation plan and monitor feeding, stress, chasing, damaged fins, and access to preferred habitat zones.

Final Recommendation

Only plan this pair if every listed condition can be met, and have a separation plan if stress or aggression appears.

Sources and Data Provenance

These references support the underlying species records used by this assessment. They do not necessarily evaluate this exact pair together.

  • fishbase.orgcare · medium confidence
  • fishbase.secare · medium confidence
  • thesprucepets.comcare · medium confidence
  • thesprucepets.comcare · medium confidence
  • en.wikipedia.orgtaxonomy · medium confidence
  • en.wikipedia.orgtaxonomy · medium confidence
  • en.wikipedia.orgtaxonomy · medium confidence
Read the full methodology and limitations
Report quality
supported
Analysis version
2026.09.1
Species data updated
Sep 29, 2026
Review status
Structured automated assessment

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