Cardinal vs Neon
Cardinals have a red stripe running the full length of the body. Neons have red only on the back half.
Cardinals grow slightly larger (1.5 inches vs 1.25 inches). They prefer warmer water (78-82°F vs 72-78°F).
Cardinals are more sensitive to ammonia and need an established tank, but once settled they live 5+ years (neons average 3).
Tank Setup
20 gallons minimum for a school of 6+. 30 gallons ideal for a proper school of 10-15.
Soft, slightly acidic water (pH 5.5-7.0, GH below 10). Heavy planting with floating plants for shade. Driftwood with tannins replicates Amazon biotope.
- ✦Use Indian almond leaves to lower pH naturally.
- ✦Avoid hard water — cardinals decline within months.
Diet
Tiny mouths require small foods. Crushed flakes, micro pellets, baby brine shrimp, and frozen daphnia.
Live food brings out the most intense color. Small portions 2-3 times daily.
Tank Mates
Other small peaceful fish: rasboras, corydoras, otocinclus, hatchetfish, dwarf gourami.
Avoid: anything that fits a 1.5-inch tetra in its mouth (angelfish, larger cichlids, gouramis).
Breeding
Difficult but possible. Need extremely soft water (GH under 5), pH 5.5, dim light. Eggs scatter and parents eat them — separate eggs immediately.
Most hobbyists buy juveniles. Wild-caught cardinals are still common in the trade.