Can Cardinal Tetra Live With Oscar?
Maybe, with caveats. Cardinal tetras are small enough for oscars to treat as food, and most oscars will eventually attempt to eat them.
Why
- Cardinal tetras reach 2 inches, well within the size range an oscar can swallow.
- Oscars grow to 12-14 inches and are aggressive cichlids with strong predatory instincts.
- Temperature overlap of 74-81F suits both species in the middle range.
- pH overlap of 6-7 works for both, though oscars tolerate wider ranges.
- Oscars are messy eaters that cloud water quickly, stressing sensitive tetras.
What could go wrong
An oscar will attempt to eat cardinal tetras eventually, usually within weeks or months of the tetras being added.
Gear for a shared tank
Sized for the 75 gallon minimum this pairing needs. Affiliate links — we earn a small commission if you buy through them.
Fluval 307 Performance Canister Filter
Oversized filtration is what lets you stock two species together without water quality crashing. Rated for a tank slightly larger than the 75 gallon minimum.
Eheim Jager 300W Thermostat Heater
Holds a steady temperature inside the 74-81°F window both species need.
API Freshwater Master Test Kit
Keep ammonia, nitrite, and nitrate in check. Two-species tanks have more bioload and less margin for error than single-species setups.
Better pairings to consider
Oscars need cichlid tankmates of similar size like convicts or jacks; cardinal tetras belong in peaceful community tanks with species under 3 inches.
Related compatibility questions
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