Cardinal Tetra tank mates
More demanding than neons. They need soft, acidic water in a settled tank three months old or more. The colour repays the wait.
Lists below are built from this species record (safest, best with, risky, unsafe) — each link opens a pair-level check, not a guarantee.
Best tank mates (on file)
Merged from conservative safest and best with fields — de-duplicated by species.
The Cardinal Tetra profile lists Corydoras Catfish as both safe and a recommended pairing. Corydoras Catfish schools in groups of 6 or more, so plan room for the whole group rather than one fish. Corydoras Catfish swims in the bottom zone while Cardinal Tetra stays in the middle, so the two will not crowd the same water column.
The Cardinal Tetra profile lists Dwarf Gourami as both safe and a recommended pairing. Dwarf Gourami is a peaceful beginner-care species with a 60L minimum. Run the pair checker for your specific tank before stocking.
The Cardinal Tetra profile lists German Blue Ram as both safe and a recommended pairing. German Blue Ram is a peaceful intermediate-care species with a 80L minimum. Run the pair checker for your specific tank before stocking.
The Cardinal Tetra profile lists Harlequin Rasbora as both safe and a recommended pairing. Harlequin Rasbora schools in groups of 6 or more, so plan room for the whole group rather than one fish.
Risky or situational
From risky tank mates and broad avoid with (excluding “unsafe” below). May work with species-only setups, more water, or mature systems — read the pair page.
None on file beyond the safe list.
Fish to avoid with Cardinal Tetra
From the unsafe list — predation, aggression, or space rules on this profile.
Oscar reaches 35cm and is flagged predatory. Cardinal Tetra at 5cm is prey-sized for it. Oscar needs at least 300L, far above the 60L minimum for Cardinal Tetra. The tank that houses one stresses the other. Oscar is rated aggressive and Cardinal Tetra is rated peaceful. No community-style planning carries that gap.
Angelfish reaches 20cm and is flagged predatory. Cardinal Tetra at 5cm is prey-sized for it. Angelfish needs at least 150L, far above the 60L minimum for Cardinal Tetra. The tank that houses one stresses the other.
Tiger Barb conflicts with Cardinal Tetra on temperament, predation, or footprint. The juvenile size in a shop tank is not the figure that matters here.
Jack Dempsey reaches 25cm and is flagged predatory. Cardinal Tetra at 5cm is prey-sized for it. Jack Dempsey needs at least 200L, far above the 60L minimum for Cardinal Tetra. The tank that houses one stresses the other. Jack Dempsey is rated aggressive and Cardinal Tetra is rated peaceful. No community-style planning carries that gap.
Tank size and groups
- Published minimum for Cardinal Tetra: 60L — group minimum 6 (schooling).
- Compatibility changes when the tank is too short for turning, too little for a real school, or too warm for one species and not the other — that is why pair checks include tank context, not only temperament.
- Nearest litre hub to this minimum: 60L hub.
Plan before you buy
Pair checks for every mix, then multi-species stocking in the builder.
Filtration & heating
A 60L minimum tank for Cardinal Tetra needs a filter rated for at least 240L/hr turnover and a heater maintaining 23–27°C.
Similar fish (same category)
- Beckford Pencilfish — min 60L
- Black Neon Tetra — min 60L
- Bloodfin tetra — min 60L
- Glowlight Tetra — min 60L
- Green neon tetra — min 60L
- Lemon Tetra — min 60L
- Silver Tip Tetra — min 60L
- X-ray tetra — min 60L
Related (care + temperament)
Other species that list Cardinal Tetra
Reverse lookup: these profiles reference Cardinal Tetra under safe or “best with” lists.