Aquarium Forge

Bolivian Ram and Cardinal Tetra Compatibility

RiskyMinimum tank for the pair: 20 gallons

Bolivian Ram and Cardinal Tetra carry a clear risk: temperature ranges overlap at 74–80°F, yet temperament or size differences mean close supervision is essential. Plan on at least 20 gallons. Individual fish vary — observe behaviour during introduction.

Bolivian Ram vs Cardinal Tetra at a glance

AspectBolivian RamCardinal Tetra
Adult size~3 in~2 in
Minimum tank20 gal20 gal
Temperature74–80°F73–82°F
pH6–7.55–7
Temperamentsemi-aggressivepeaceful
Swimming zonebottommiddle
Group size2+6+
Care leveleasymoderate

Overlap in temperature: 74–80°F. Overlap in pH: 6–7.

Why this verdict

  • Temperature: Shared range of 74–80°F.
  • Water parameters: Shared pH range of 6–7.
  • Temperament: Bolivian Ram can be territorial; provide plants, sight breaks, and space.
  • Adult size: Comparable adult sizes (~3" and ~2").
  • Swimming zone: Complementary layers (bottom + middle) reduce competition for space.
  • Schooling: Group sizes matter: Bolivian Ram: keep at least 2; Cardinal Tetra: keep at least 6.
  • Tank size: Plan for at least 20 gallons to satisfy both species.

Main risks

  • Occasional chasing or fin nipping is possible.

Recommended tank

Plan on 20 gallons or larger for this pair. Suitable sizes: 20 gallon High, 20 gallon Long, 29 gallon.

Group sizes: Bolivian Ram: keep at least 2; Cardinal Tetra: keep at least 6.

Sources

  • FishBaseScientific Database · Primary / scientific · https://www.fishbase.se/
  • SeriouslyFishSpecialist Publication · High authority · https://www.seriouslyfish.com/
  • Aquarium Forge editorial guidelinesEditorial Interpretation · Editorial interpretation
  • FishBaseScientific Database · Primary / scientific · https://www.fishbase.se/
  • SeriouslyFishSpecialist Publication · High authority · https://www.seriouslyfish.com/
  • Aquarium Forge editorial guidelinesEditorial Interpretation · Editorial interpretation
  • Aquarium Forge editorial guidelinesEditorial Interpretation · Editorial interpretation

Compatibility verdicts are planning guidance, not guarantees — individual fish vary. Rule version 1.1 · Data reviewed: .

Frequently asked questions

Can Bolivian Ram and Cardinal Tetra live together?

Our verdict is “Risky”. Bolivian Ram and Cardinal Tetra carry a clear risk: temperature ranges overlap at 74–80°F, yet temperament or size differences mean close supervision is essential. Plan on at least 20 gallons. Individual fish vary — observe behaviour during introduction.

What tank size do Bolivian Ram and Cardinal Tetra need?

Plan for at least 20 gallons so both species have their minimum space — Bolivian Ram needs 20+ gal and Cardinal Tetra needs 20+ gal. Adding length and cover reduces stress further.

What temperature do Bolivian Ram and Cardinal Tetra share?

Their comfortable ranges overlap at 74–80°F. Hold the tank near the middle of that band and avoid the extremes of either species' range.

What are the main risks keeping Bolivian Ram with Cardinal Tetra?

Occasional chasing or fin nipping is possible.

How many Bolivian Ram and Cardinal Tetra should I keep?

Bolivian Ram: keep at least 2; Cardinal Tetra: keep at least 6. Group sizes matter for shoaling fish — too few and they become stressed and nippy.

Canonical https://aquariumforge.com/compatibility/bolivian-ram/cardinal-tetra/