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A shoal of neon tetras glowing against green plants is one of the classic aquarium sights. Neons are peaceful and small, but they're more delicate than their reputation suggests. They do best in a mature, stable tank.
Neon tetras at a glance
| Size | 3–4cm |
| Minimum tank | 60 litres |
| Shoal size | At least 8–10 |
| Temperature | 22–26°C |
| pH | 6.0–7.2, soft water preferred |
| Lifespan | 5+ years with good care |
Neon vs cardinal tetra
The neon tetra has a red stripe that runs only halfway along the body. The cardinal tetra has red along the whole lower body, grows slightly larger and prefers warmer water (24–28°C). There are also diamond neons, black neons and green neons.
Setting up the tank
- Add neons to a mature tank. They're sensitive to ammonia and swings in water chemistry. Wait until the tank has been cycled and stable for at least a month. See How to Cycle Your Aquarium.
- Dark substrate and plants make neons feel secure and show off their colour. Try planted substrates and live plants.
- Soft, slightly acidic water suits them best. Driftwood and catappa leaves help lower pH naturally and tint the water. Read our guide to pH, GH and KH.
- Gentle flow and dim or shaded lighting.
Feeding
Neons have small mouths. Feed fine flake or micro pellets such as Hikari Micro Pellets, plus small frozen foods such as daphnia and baby brine shrimp. Feed once or twice daily, only what's eaten in a couple of minutes.
Best tankmates
Choose small, peaceful fish: corydoras, rasboras, other small tetras, honey gouramis, otocinclus and shrimp. Avoid anything with a mouth big enough to swallow them, including adult angelfish in some tanks. See our compatibility guide.
Common problems
- Losses after adding to a new tank: the most common issue. Patience and a mature filter prevent it.
- Faded colour: often stress, bright light or poor water. Colours return when conditions improve.
- Neon tetra disease: a parasite that causes pale, whitish patches under the skin and a bent spine. There's no reliable cure, so remove affected fish quickly and quarantine new arrivals. See Setting Up a Quarantine Tank.
- White spot: see our white spot guide.
