| Temperature | 24–28 °C (75–82 °F) |
|---|---|
| pH | 4.0–6.0 |
| Min tank | 10 gal (38 L) |
| Adult size | 3 cm |
| Lifespan | 5–7 years |
Most people buy a Green neon tetra on looks alone, then wonder why it sulks. The fish is fine; the setup around it usually is not. The Paracheirodon simulans Green neon tetra is a long-time favourite for a reason, but it has specific needs that generic "community fish" advice misses.
At a glance
| Minimum tank | 10 gallons (38 L) |
|---|---|
| Temperature | 24 to 28 °C |
| pH range | 4.0 to 6.0 |
| Adult size | 3 to 3 cm |
| Lifespan | 5 to 7 years |
| Group size | a group of 8+ |
Where it comes from
In the wild the Green neon tetra lives in slow, vegetated waters where cover is everywhere and currents stay gentle. Recreating that means planting densely, keeping the filter flow soft, and avoiding bright, open tanks that leave the fish exposed. Stable water matters more than perfect parameters.
Tank setup
Start with at least 10 gallons and a mature, cycled filter — see the tiger lotus in low light before you buy. A sand or fine gravel substrate, a few driftwood branches and a carpet or mid-ground plant mass give the fish somewhere to retreat. Keep nitrates under 20 ppm with a weekly 28% water change.
Feeding
Feed a varied diet: a quality flake or micro-pellet as the base, topped up with frozen or live foods two or three times a week. Offer only what the fish clears in about 1 minutes, once or twice daily. Overfeeding is the single most common cause of water-quality swings.
A mistake everyone makes
Adding a Green neon tetra to a brand-new tank is the classic error. An uncycled tank spikes ammonia to 1.5 ppm within days and the fish pays for it. Cycle first, stock lightly, and let the group size build up gradually.
Good tank mates
Peaceful, similar-sized neighbours work best. Avoid fin-nippers and anything large enough to swallow the Green neon tetra. A planted community with a solid internal nematodes in a planted tank in the mix tends to settle quickly.
In a planted tank
A densely planted 10-gallon setup suits the Green neon tetra well: the plants soften the light and give cover, while the fish's foraging stirs the substrate. Keep nitrates under 20 ppm and trim so the Green neon tetra still has open swimming lanes.
