Fish guide

Neon Tetra

Paracheirodon innesi

Neon Tetra

Quick Reference

Difficulty
Easy to moderate. Hardy once acclimated, but newly purchased fish can be sensitive to immature aquariums and sudden parameter changes.
Adult Size
About 1–1.5 inches (2.5–4 cm) total length
Minimum Tank
10 gallons for a small group; 15–20 gallons or larger is preferred for a proper school and more stable water quality.
Temperature
70–78°F (21–26°C); around 72–76°F (22–24°C) is a good long-term target.
pH
6.0–7.5 for most captive-bred fish; slightly acidic to neutral water is preferred.
GH
1–10 dGH; soft to moderately hard water
KH
1–6 dKH; avoid unstable, near-zero buffering unless the aquarium is carefully managed.
Temperament
Peaceful
Diet
Omnivore / micropredator
Swimming Level
Primarily middle level
Social Type
Shoaling fish that displays natural schooling behavior in larger groups
Minimum Group
At least 6; 8–12 or more is strongly preferred.
Community Safe
Yes, with peaceful tank mates of a similar size and compatible temperature requirements.
Plant Safe
Yes

Key Takeaways

  • Difficulty: Easy to moderate. Hardy once acclimated, but newly purchased fish can be sensitive to immature aquariums and sudden parameter changes.
  • Minimum tank size: 10 gallons for a small group; 15–20 gallons or larger is preferred for a proper school and more stable water quality.

Habitat

Natural Habitat: Shaded, slow-moving blackwater and clearwater forest streams and tributaries with leaf litter, submerged roots, woody debris, and overhanging vegetation.

Natural Water Conditions: Very soft, acidic water, often stained with tannins; approximately 68–79°F (20–26°C), pH 5.0–7.0, and very low mineral content in many native habitats.

Other Habitat Notes: Wild habitats are generally dim. The substrate is often dark and covered with decomposing leaves, while dense streamside vegetation filters sunlight.

Aquarium

Tank Size Notes: Floor length matters more than height. A longer tank provides schooling room, and a larger water volume reduces rapid changes in temperature and chemistry.

Tank Shape: A standard rectangular aquarium with good horizontal swimming length

Substrate: Sand or fine, smooth gravel; a dark substrate helps the fish feel secure and makes their colors stand out.

Plants: Use live plants around the sides and back, with open space through the center. Java fern, Cryptocoryne, Anubias, Amazon swords, and floating plants are suitable choices.

Hardscape: Driftwood, smooth branches, rounded stones, and optional dried leaf litter

Hiding Places: Plant thickets, shaded areas beneath wood, and floating-plant cover

Swimming Space: Maintain an open middle section or open front-to-back lane for group movement.

Water Flow: Gentle to moderate; avoid forcing the school to fight a strong current continuously.

Lighting: Low to moderate. Bright lighting should be softened with plants, wood, or floating cover.

Lid Required: Recommended. Neon tetras are not notorious jumpers, but any small, startled fish can leave an uncovered aquarium.

Other Setup Notes: Add neon tetras only to a fully cycled, biologically mature aquarium. Keep ammonia and nitrite at 0 ppm, maintain low nitrate, and prioritize stability over chasing an exact pH.

Behavior

General Behavior: Active but gentle. They move through the midwater in loose shoals and form tighter schools when startled or when the aquarium is spacious.

Aggression: Very low; occasional brief chasing may occur within the group but rarely causes harm in an adequately sized school.

Territorial: No

Schooling/Social Behavior: They are shoaling fish. A larger group increases confidence, improves natural behavior, and reduces stress-related hiding.

Group Requirements: Keep 6 as an absolute minimum, preferably 8–12 or more. Do not keep a single neon tetra.

Notable Behaviors: Their reflective blue stripe may appear dim at night, during stress, or shortly after the lights turn on. This temporary color change can be normal.

Frequently Asked Questions

Can neon tetras live with bettas?

Sometimes, but compatibility depends on the individual betta, tank size, planting, and temperature. Provide ample cover and an appropriate school, and be prepared to separate the fish if chasing or stress occurs.

Sources and Further Reading

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