Overview
The neon tetra is a tiny, peaceful schooling fish from the blackwater streams of the western Amazon basin. Its iridescent blue-green stripe and red rear half are structural colours that seem to glow, and a tight school moving in unison is one of the hobby's signature sights.
Neons are hardy once established but sensitive to poor or unstable water, so they belong in a mature, cycled aquarium. They are shoaling fish that feel safe , and look their best , only in numbers.
| Care level | Beginner |
| Adult size | 1.2-1.5 in (3-4 cm) |
| Lifespan | 5-8 years |
| Temperament | Peaceful |
| Min. tank | 10 gal (38 L) |
| Temperature | 70-81°F (21-27°C) |
| pH | 6.0-7.0 |
| Hardness | 1-10 dGH |
| Diet | Omnivore |
| Schooling | Yes , keep 6 or more |
Water & tank conditions
Neons come from soft, acidic, warm blackwater. Aim for pH 6.0-7.0, soft to moderate hardness, and 70-81°F. They are best added to an already-cycled, stable tank; sudden swings cause stress and colour loss.
Aquascape & setup
A densely planted tank with a dark substrate and some floating plants makes the colours pop and gives the school open swimming lanes in the middle water column. Driftwood and botanicals that tint the water gently recreate their natural blackwater home.
Diet & feeding
Neons are micro-predators and omnivores. Feed small, high-quality flakes or micro-pellets plus frequent frozen or live daphnia, cyclops, baby brine shrimp and crushed bloodworms. Their small mouths need appropriately small foods.
Tankmates & schooling
Keep at least six , more is better , or they become skittish and dull. Ideal tankmates are other small, peaceful species: other tetras, rasboras, corydoras, dwarf gouramis and shrimp. Avoid large or aggressive fish that will eat them (including angelfish, which hunt neons in the wild).
Breeding
Breeding is possible but finicky: very soft, acidic, dim water triggers spawning, and the eggs and fry are light-sensitive. A separate breeding tank and infusoria for the fry are needed for any real success.
Fun facts
- The blue stripe is a structural colour , it reflects light rather than using pigment, so it appears to glow.
- Neons can dim their stripe at night or when stressed and 'switch it back on' in the morning.
- They are named for innes, and the similar cardinal tetra has a fuller red belly stripe.
- In the wild they live in soft, tea-stained blackwater beneath the Amazon canopy.
- A frightened school tightens and moves as one , a defence that confuses predators.
Frequently asked questions
How many neon tetras should I keep together?
Keep a minimum of six, and ideally 10 or more. Neon tetras are shoaling fish; in small numbers they become stressed, pale and hide, while a large group is confident and colourful.
Are neon tetras good for beginners?
Yes, once your tank is fully cycled and stable. They are hardy and peaceful, but they are sensitive to poor or fluctuating water, so they should not be added to a brand-new, un-cycled tank.
What is the difference between neon and cardinal tetras?
Both have a blue stripe, but the cardinal tetra's red stripe runs the full length of its body, while the neon tetra's red only covers the rear half. Cardinals are slightly larger and prefer warmer, softer water.
What tank size do neon tetras need?
A group of neons needs at least a 10-gallon (38-litre) tank, with more space for larger schools or community setups.
Will neon tetras breed in a community tank?
Rarely successfully. They need very soft, acidic, dim water to spawn, and adults and other fish eat the eggs, so a dedicated breeding tank is required.
