Fish care
Cardinal Tetra: Complete Care Guide
Last updated: May 2026
Structured care sheet for Cardinal tetra (Paracheirodon axelrodi). Validate every purchase with the free aquarium stocking calculator, parameter testing habits, and the species database table.
- Cross-check length and temperature against the species explorer.
- Track nitrate drift weekly once the tank has cycled.
- Refer to the species hub for long-form tank mate essays.
Blackwater temperament
Compared with neons, cardinals tolerate warmer, softer water and show deeper blue–red contrast when tannins or botanicals gently acidify the environment. That does not mean peat sludge—stability beats chasing a colour grade on the first day.
Shipping stress
They often arrive lean from long supply chains. Offer micro foods, dim light for the first week, and resist crowding them with boisterous barbs until body condition recovers.
See tank mate combinations tuned to temperament overlap.
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