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Compatibility Report

Can Common Goldfish Live With Green Severum?

GuideMyTank compatibility analysis for Common Goldfish and Green Severum.

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.
  • One species may be semi-aggressive and require planning.
  • Water hardness preferences conflict.
  • Specialist tank style requirements need careful matching.
  • Territorial footprint and swimming zone overlap require extra space and cover.
  • Breeding aggression can turn an otherwise workable pairing into a caution setup.

Supporting factors

  • pH requirements overlap well.
  • Social requirements align.
  • No predation risk detected.
  • Tank size requirements align.
Common Goldfish profileGreen Severum profileMethodology and limitations

Why This Pair Received Its Verdict

Common Goldfish and Green Severum receive a conditional verdict from the current structured assessment. Common Goldfish is recorded as peaceful with an aggression level of 1/10; Green Severum is recorded as semi-aggressive with an aggression level of 5/10. 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 requirements overlap well.
  • One species may be semi-aggressive and require planning.
  • Social requirements align.

Helpful Links

Use the Compatibility CheckerRead the Compatibility Disclaimer

Water Parameter Overlap

Common Goldfish has a recorded temperature range of 60–75°F and pH range of 7–8.4. Green Severum is recorded at 75–84°F and pH 6–7.5. Their shared planning window is 75–75°F for temperature and 7–7.5 for pH. A shared aquarium must stay inside the overlap rather than merely touching each species’ outer tolerance.

Aquarium Space and Adult Size

Common Goldfish sets the larger listed base aquarium requirement at 75 gallons; the other listed minimum is 75 gallons. Common Goldfish is the larger adult by the recorded maximum, reaching 12 inches, compared with 10 inches. These figures are starting constraints, not a stocking-capacity calculation, because the complete group sizes and bioload still matter.

Behavior and Social Requirements

Common Goldfish is a moderate species associated with the mid zone and moderate flow. Green Severum is moderate, uses the mid zone, and has a moderate flow preference. Common Goldfish does not have a recorded minimum school larger than one, while green severum does not have a recorded minimum school larger than one. The aquarium must support both social structures without forcing either species into insufficient space.

Husbandry Fit

Common Goldfish is recorded as a omnivore with easy care, while Green Severum is a omnivore with intermediate care. Their listed preferred tank styles are goldfish and community. 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 Common Goldfish and Green Severum; 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 75–75°F.
  • Keep pH within 7–7.5.
  • Use at least the larger 75-gallon base requirement before accounting for the complete stocking plan.
  • Common Goldfish does not have a recorded minimum school larger than one; green severum does not have a recorded minimum school larger than one.
  • 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.

  • ornamentalfish.orgcare · medium confidence
  • fishbase.secare · medium confidence
  • thesprucepets.comcare · 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
Jul 2, 2026
Review status
Structured automated assessment

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