Neon Tetras (Paracheirodon innesi) are one of the most recognisable freshwater fish in the world, defined by the vivid iridescent blue-green stripe running horizontally from nose to adipose fin and the bright red patch covering the rear half of the body and tail. In a school of ten or more moving through a planted tank the collective flash of blue and red is one of the most visually dramatic effects achievable in a home aquarium at this price point. They are small, peaceful, and well-suited to community tanks with compatible tankmates. Wildly popular for decades and for good reason -- easy to source, easy to keep in the right conditions, and immediately striking in any planted setup.
6.0–7.0pH
2–10GH (dGH)
68–78°FTemperature
1.5 inMax Size
Appearance & Schooling
The Neon Effect
The iridescent blue stripe is structural colour, not pigment -- it shifts and flashes as the fish moves. The blue-green stripe of the Neon Tetra is produced by light interference in specialised cells rather than by pigment alone, which means it shifts in intensity and hue depending on the viewing angle and light source. A school of Neons moving through a planted tank catches and releases light as they turn, producing a collective flickering effect that no static colour can replicate.
School of 6 minimum, 10 or more strongly recommended. Neon Tetras are obligate schooling fish and show stress, colour fading, and reduced activity in small groups. A school of 10 or more produces the full schooling behaviour -- tight formation swimming, synchronised turns, and the collective colour display the species is known for. In groups below 6 the fish scatter, hide more frequently, and show noticeably less vivid colouration.
Colours fade when stressed, ill, or kept in poor conditions. The vividness of the blue stripe and red patch are reliable health indicators. Pale, washed-out colouration in an established school is a signal to check water parameters, temperature stability, and tankmate stress.
Shrimp Compatibility
Can They Be Kept with Shrimp?
Adult Neocaridina shrimp are generally safe -- shrimplets and small juvenile shrimp are at risk. Neon Tetras are small but opportunistic feeders and will consume shrimplets and very small juvenile shrimp. Adult Neocaridina at full size (2cm or more) are typically too large to be targeted, but any shrimp small enough to fit in a Neon's mouth is potential food. If maintaining a breeding shrimp colony, dense planting with Java Moss and Subwassertang gives shrimplets hiding cover that significantly reduces predation losses.
Caridina shrimp are higher risk due to smaller adult size. Crystal Red and Crystal Black Shrimp are smaller than Neocaridina at maturity and overlap more with the size range Neon Tetras will target. A heavily planted Caridina tank can work, but predation on juveniles should be expected and colony growth will be slower than in a fish-free setup.
Parameter overlap is imperfect but workable in a soft-water planted setup. Neon Tetras prefer soft, slightly acidic water (pH 6.0 to 7.0, GH 2 to 10) which aligns reasonably well with Neocaridina parameters and closely with Caridina parameters. Avoid keeping Neons in the harder, more alkaline end of the Neocaridina range if both species are to thrive long-term.
Keeper's NoteNeon Tetras are most impressive in a densely planted tank with dark substrate and subdued lighting -- conditions that also happen to be ideal for shrimp. The contrast between the electric blue stripe and a dark background is dramatically more vivid than the same fish in a brightly lit bare tank. If you are building a shrimp display tank and want to add fish movement and colour, a school of 10 to 15 Neons is one of the most effective and visually balanced additions available.
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