Cardinal tetra Tetras & Small Schools — Variety Guide

Cardinal tetra — one of the tetras & small schools varieties owners search for by name.

Cardinal tetra Tetras & Small Schools — photo used in our Tetras & Small Schools guide

Cardinal tetra is one of the tetras & small schools varieties people look up by name. This page answers the questions owners actually type about cardinal tetra, then points you to the sourced tetras & small schools care guidance that applies to every variety.

Schooling fish — the rule is six or more, always.

Quick answer: Cardinal tetra is a variety of tetras & small schools. Everything on this page is tetras & small schools-level guidance — we do not invent variety-specific numbers.

The care below is tetras & small schools-level guidance from our species hub, sourced to Merck Veterinary Manual — Exotic & Laboratory Animals: Aquarium Fish and RSPCA — Aquarium fish advice. It applies to Cardinal tetra exactly as it applies to every other tetras & small schools variety. We do not publish variety-specific temperament, lifespan or weight numbers that we cannot source.

Feeding and the health watchlist

Micro-pellets, crushed flake, frozen bloodworms and brine shrimp — small mouths, small portions, twice daily. Watch for: ich (white spots — raise to treatment temperature per product directions), neon tetra disease (fading color patch, asymmetric swimming — incurable; remove affected fish), fin nipping (usually a sign the school is too small or the tank too empty), and wasting in old wild-caught stock. Quarantine new fish 3–4 weeks; it prevents most heartbreak.

Choosing species honestly

Beginner-safe: neons, cardinals, embers, black skirts, bloodfins, glowlights — all peaceful and forgiving. Special-case: rummy-nose (excellent water-quality indicator, sensitive), Congo tetras (bigger, 90 cm+ tank), serpae tetras (fin-nippers in small groups — 10+ calms them), bucktoothed tetras (not community fish — aggressive carnivores; avoid). Cardinais vs neons: cardinals are more colorful and slightly hardier but cost more and prefer warmer water.

What people ask about Cardinal tetra