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Compatibility Report

Can Discus Live With Swordtail?

GuideMyTank compatibility analysis for Discus and Swordtail.

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

  • Temperature ranges have limited overlap.
  • pH ranges have limited overlap.
  • One species requires a significantly larger aquarium.
  • Water hardness preferences conflict.
  • GH or KH ranges do not overlap well.
  • A species needing stable water has only a narrow pH, GH, or KH overlap.
  • Activity level or feeding speed may stress a slow, delicate, or long-finned species.
  • Specialist tank style requirements need careful matching.

Supporting factors

  • Species have similar temperament.
  • Both species have compatible schooling or group behavior.
  • No predation risk detected.
Discus profileSwordtail profileMethodology and limitations

Why This Pair Received Its Verdict

Discus and Swordtail receive a conditional verdict from the current structured assessment. Discus is recorded as peaceful with an aggression level of 2/10; Swordtail 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 have limited overlap.
  • pH ranges have limited overlap.
  • Species have similar temperament.
  • Both species have compatible schooling or group behavior.

Helpful Links

Use the Compatibility CheckerRead the Compatibility Disclaimer

Water Parameter Overlap

Discus has a recorded temperature range of 82–86°F and pH range of 4.5–6.5. Swordtail is recorded at 72–82°F and pH 6.5–8. Their shared planning window is 82–82°F for temperature and 6.5–6.5 for pH. A shared aquarium must stay inside the overlap rather than merely touching each species’ outer tolerance.

Aquarium Space and Adult Size

Discus sets the larger listed base aquarium requirement at 75 gallons; the other listed minimum is 30 gallons. Discus is the larger adult by the recorded maximum, reaching 8 inches, compared with 5.5 inches. These figures are starting constraints, not a stocking-capacity calculation, because the complete group sizes and bioload still matter.

Behavior and Social Requirements

Discus is a calm species associated with the mid zone and low flow. Swordtail is active, uses the top zone, and has a moderate flow preference. Discus should be planned as a group of at least 6, while swordtail should be planned as a group of at least 4. The aquarium must support both social structures without forcing either species into insufficient space.

Husbandry Fit

Discus is recorded as a omnivore with advanced care, while Swordtail is a omnivore with easy 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 Discus and Swordtail; 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 82–82°F.
  • Keep pH within 6.5–6.5.
  • Use at least the larger 75-gallon base requirement before accounting for the complete stocking plan.
  • Discus should be planned as a group of at least 6; swordtail should be planned as a group of at least 4.
  • 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.secare · medium confidence
  • fishbase.secare · medium confidence
  • en.wikipedia.orgtaxonomy · medium confidence
  • en.wikipedia.orgtaxonomy · medium confidence
  • en.wikipedia.orgtaxonomy · medium confidence
  • es.wikipedia.orgtaxonomy · medium confidence
  • es.wikipedia.orgtaxonomy · medium confidence
Read the full methodology and limitations
Report quality
supported
Analysis version
2026.09.1
Species data updated
Jul 2, 2026
Review status
Structured automated assessment

Related Resources

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