What tank size does a Emperor Tetra need?

A Emperor Tetra needs an aquarium of at least 75 litres (19.8 US gallons) with a footprint at least 80 cm (31.5 in) long — for this species, swimming length matters as much as raw volume.

What water parameters does a Emperor Tetra need?

Emperor Tetra does best at 23–27 °C (73.4–80.6 °F), pH 5.5–7.5 and a general hardness of 2–18 °dGH.

What group size does a Emperor Tetra need?

Emperor Tetra is a social species — keep a group of at least 6 so natural behaviour emerges and stress stays low.

Is the Emperor Tetra suitable for beginners?

Yes — Emperor Tetra is one of the easier species to keep and forgives typical first-tank mistakes, as long as the aquarium is cycled and maintained.

Species library

Emperor Tetra

Nematobrycon palmeri

Characidae

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

📷 7TP (Krzysztof Bartosik) · CC BY-SA 4.0 · resized · Wikimedia Commons

Emperor Tetra — Nematobrycon palmeri — 📷 7TP (Krzysztof Bartosik) · CC BY-SA 4.0 · resized · Wikimedia Commons

About

The emperor tetra is a hardy, elegant characin from the Atrato and San Juan river basins of western Colombia, prized for its purple-blue body sheen, bold dark lateral stripe and the trident-shaped tail extension of dominant males. Slightly larger and sturdier than most nano tetras, it is peaceful and community-safe, though rival males stake out small territories and spar harmlessly among themselves in a spacious, well-planted tank. Kept in a good-sized group it settles quickly and displays confident, glittering colour.

Care

Keep in a shoal of 6 or more (10+ is better) in a soft to neutral, slightly acidic, well-planted tank of at least 75 L with gentle flow and some shade. Males are mildly territorial with one another but not aggressive toward tankmates; provide open swimming room and cover to diffuse minor sparring.

Diet

Micropredatory omnivore that grazes small invertebrates and zooplankton; feed varied dry foods plus frequent frozen or live daphnia, cyclops, artemia and bloodworm for colour and condition.

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 Emperor Tetra need?: A Emperor Tetra needs an aquarium of at least 75 litres (19.8 US gallons) with a footprint at least 80 cm (31.5 in) long — for this species, swimming length matters as much as raw volume.
What water parameters does a Emperor Tetra need?: Emperor Tetra does best at 23–27 °C (73.4–80.6 °F), pH 5.5–7.5 and a general hardness of 2–18 °dGH.
What group size does a Emperor Tetra need?: Emperor Tetra is a social species — keep a group of at least 6 so natural behaviour emerges and stress stays low.
Is the Emperor Tetra suitable for beginners?: Yes — Emperor Tetra is one of the easier species to keep and forgives typical first-tank mistakes, as long as the aquarium is cycled and maintained.

Sources

Water & tank

Temperature23–27°C

Optimal temp.24–26°C

pH5.5–7.5

Hardness (GH)2–18°d

Carbonate (KH)0–10°d

Adult size5.5 cm

Min. volume≥ 75 L

Min. tank length≥ 80 cm

Group size≥ 6

Swimming zoneMid

TemperamentPeaceful

Water typeFreshwater

FlowLow

Lifespan~5 yrs

Try in the calculator