Keeping Cardinal Tetras: The Jewel of the Planted Tank

Cardinal tetras are the neon tetra turned up to full brilliance: larger, with a glowing red stripe that runs the entire length of the body rather than half. A shoal of them in a well-planted, softly lit tank is one of the most beautiful sights in the hobby. They ask for slightly warmer, softer, more stable water than neons, rewarding a mature planted setup.

Is it right for you?

Cardinal tetras suit a keeper with a mature, stable planted tank who wants maximum color. They are a little more delicate than neons but not difficult once conditions are right.

System & Space

A warm, softly lit, well-planted community tank suits them; they need room for a shoal and plenty of cover. A mature tank suits them better than a new one.

Water & Temperature

They like warm, soft, slightly acidic water - warmer than neons - and stability; blackwater-style tanks show them at their best. Avoid hard alkaline water and swings.

Stocking & Feeding

Keep a school of six or more (more is better) and feed small flakes and micro-foods; they eat readily. A larger shoal displays and colors up beautifully.

Health & Care

Hardy in warm, soft, mature water; the risks are un-cycled tanks, cold or hard water, and poor stock. Buy healthy fish and quarantine when possible.

Harvest & Enjoying Them

Ornamental - the reward is a dazzling shoal that defines a planted aquascape; breeding them is a rewarding challenge for experienced keepers.

Getting Started

Add a school of six or more to a mature, cycled, warm soft-water planted tank and let them settle in.

Common Mistakes

Cold or hard water, an immature tank, and too small a school are the usual mistakes.

FAQ

Neon or cardinal? Cardinals are larger, redder along the full body, and like it warmer and softer.

Are they hard to keep? Not once the tank is mature and stable.