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Compatibility

Compatibility brief

Can Cardinal Tetra live with Discus?

Cardinal Tetra

Cardinal Tetra

Paracheirodon axelrodi

peaceful~5cm
Discus

Discus

Symphysodon sp.

peaceful~20cm
VerdictRISKY

Risky. This mix is commonly discouraged for typical setups.

Cardinal Tetra + Discus: Incompatible temperature requirements. Cardinal Tetra needs 23–27°C and Discus needs 28–32°C. Their ranges do not overlap. Real tanks add variables Fishori cannot model; treat this as a high-risk read, not certainty.

Compatibility score

30/100

Profile confidence: medium

Order of checkstank volume vs adults → predation mouth gap → temperament / fin nipping → shared water windows.

Min tank

200L

Combined minimum footprint reference for these two species: about 200L (larger active fish often want more length).

Temperature
Range in °CNo shared window
Cardinal TetraDiscus
pH
Range6–7 shared
Cardinal TetraDiscusShared window

Assessment details

  1. Compatible temperaments

    Both Cardinal Tetra and Discus share a peaceful temperament.

  2. Incompatible temperature requirements

    Top issue

    Cardinal Tetra needs 23–27°C and Discus needs 28–32°C. Their ranges do not overlap.

“Cardinal Tetra needs 23–27°C and Discus needs 28–32°C”

Incompatible temperature requirements

Next steps

Concrete changes, not "research more" filler.

  • •Cardinal Tetra should be kept in a group of at least 6 for best health and behaviour.
  • •Discus should be kept in a group of at least 4 for best health and behaviour.
  • •These fish cannot be comfortably housed together. Their temperature needs are incompatible.
Sources from both profiles
Only URLs that exist on the species records are shown. We do not fabricate citations.

Try this next

Build the full stocking list with Cardinal Tetra + Discus

Compare another pairOpen tank builder

Plan further

Check each species’ mates list, size the glass, then verify the full stock in the builder. Methodology explains how verdicts are produced.

Individual fish vary in personality. Fishori uses conservative hobby rules. Observe any new introduction closely, feed thoughtfully, and keep a quarantine or backup plan. This is not veterinary advice.

Profile data confidence: high. Checked against several solid care sources that mostly agree.

Full tank-mate guides

Related pair checks

Other tank mates for Cardinal Tetra

Cardinal Tetra + Discus — common questions

Can Cardinal Tetra live with Discus?
For most keepers, no. The verdict is RISKY: at least one check fails hard for a typical home tank. Choose a different pairing, or read the assessment details on this page to see exactly what fails before deciding.
What tank size do you need for Cardinal Tetra and Discus together?
Plan around 200 litres as the working minimum. That figure comes from each species' published minimum and their group needs, and it assumes adult sizes, not shop sizes.
What's the main risk?
Incompatible temperature requirements. That is the check that fails outright for this pair. The matching entry under assessment details on this page explains the reasoning and the numbers behind it.
What should you check before buying?
Cardinal Tetra should be kept in a group of at least 6 for best health and behaviour. Discus should be kept in a group of at least 4 for best health and behaviour.