What tank size does a Green Neon Tetra need?

A Green Neon Tetra needs an aquarium of at least 40 litres (10.6 US gallons) with a footprint at least 45 cm (17.7 in) long — for this species, swimming length matters as much as raw volume.

What water parameters does a Green Neon Tetra need?

Green Neon Tetra does best at 23–30 °C (73.4–86 °F), pH 4–7.5 and a general hardness of 1–8 °dGH.

What group size does a Green Neon Tetra need?

Green Neon Tetra is a social species — keep a group of at least 10 so natural behaviour emerges and stress stays low.

Is the Green Neon Tetra suitable for beginners?

Green Neon Tetra sits in the middle of the difficulty scale — manageable for a careful beginner who has done the reading, but it has specific needs worth researching first.

Species library

Green Neon Tetra

Paracheirodon simulans

Characidae

FishDifficulty: ●●●○○Data: well-established

📷 Atulbhats · CC BY-SA 4.0 · resized · Wikimedia Commons

Green Neon Tetra — Paracheirodon simulans — 📷 Atulbhats · CC BY-SA 4.0 · resized · Wikimedia Commons

About

The green neon tetra is the smallest of the three Paracheirodon species, reaching barely 2.5 cm, and comes from blackwater tributaries of the upper Rio Negro and Orinoco. It is a distinct species rather than a variety of the neon or cardinal tetra: its stripe is green rather than blue, covers more of the head, runs right back to the caudal-fin base, and the red on the flank is duller and far less extensive. Wild-caught and adapted to very soft, acidic, warm water, it wants noticeably higher temperatures than the neon tetra it is so often shelved beside.

Care

Keep a group of at least 10 in warm (26-28 °C), soft, acidic water with gentle flow, dark substrate and dense planting. Tankmates must be small and calm - anything with a real mouth on it will eat them.

Diet

Micropredator taking tiny crustaceans and insect larvae in the wild; feed crushed flake, nano pellets, frozen cyclops and baby brine shrimp.

Tankmate compatibility

Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.

Telling males from females

What works for this species, most reliable first.

Belly depthA hint only · only on well-fed adults, and only as a comparison
For most tetras, barbs and rasboras this is all there is: a conditioned female is deeper through the belly than a male of the same length.

All the methods, with diagrams

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Frequently asked questions

What tank size does a Green Neon Tetra need?: A Green Neon Tetra needs an aquarium of at least 40 litres (10.6 US gallons) with a footprint at least 45 cm (17.7 in) long — for this species, swimming length matters as much as raw volume.
What water parameters does a Green Neon Tetra need?: Green Neon Tetra does best at 23–30 °C (73.4–86 °F), pH 4–7.5 and a general hardness of 1–8 °dGH.
What group size does a Green Neon Tetra need?: Green Neon Tetra is a social species — keep a group of at least 10 so natural behaviour emerges and stress stays low.
Is the Green Neon Tetra suitable for beginners?: Green Neon Tetra sits in the middle of the difficulty scale — manageable for a careful beginner who has done the reading, but it has specific needs worth researching first.

Sources

Water & tank

Temperature23–30°C

Optimal temp.26–28°C

pH4–7.5

Hardness (GH)1–8°d

Carbonate (KH)0–4°d

Adult size2.5 cm

Min. volume≥ 40 L

Min. tank length≥ 45 cm

Group size≥ 10

Swimming zoneMid

TemperamentPeaceful

Water typeFreshwater

FlowLow

Lifespan~4 yrs

Try in the calculator