Description
The glowlight tetra is recognised by a single line: a golden-orange band running along the flank from the eye to the tail that glows like a lit filament. It measures about 4 cm and is one of the hardiest characins in the trade, which is why it is so often recommended for beginners.
Every fish on sale is farm-bred; the wild fish is known only from the Essequibo river in Guyana. Mass breeding has made it tolerant of water conditions, but the colour is better in acidic water, with dim light and plants.
Behavior
Peaceful and shoaling: with fewer than six it hides and loses colour; with ten or more it swims in the middle zone and shows itself.
It lives well with other small tetras, rasboras, corydoras, otocinclus and dwarf gourami.
Avoid housing it with medium or large cichlids, which will eat it, and with fast or nipping fish that stress it.
Habitat
Hemigrammus erythrozonus is known only from the Essequibo river in Guyana, where it lives mainly in forest tributaries with water stained brown by tannins and very acidic.
It shows in the aquarium: driftwood, dried beech or oak leaves, dim light and dense planting display it far better than a bare set-up, where it looks washed out.
Tetra luminoso is a schooling species, which means that in the wild it lives and moves in large, coordinated groups.
Keep at least 6 individuals so they feel comfortable and their stress level stays low.
Details
🌊 Water parameters
🐠 Minimum tank size
Breeding
An egg scatterer with no parental care: it scatters the eggs among fine plants and the adults eat them. Breeding it takes a separate tank with soft, acidic water, dim light and a mesh or moss where the eggs can fall.
The fry hatch within a day or two and start on infusoria before moving on to brine shrimp nauplii.
Diet
A small-mouthed omnivore, like characins of its size.
- Staple: fine flake or micropellets.
- Supplement: frozen daphnia, brine shrimp or mosquito larvae several times a week.
Whatever it does not eat within a couple of minutes should be removed.
What about your tank?
Enter your tank's values to see only the compatible species that fit them. Litres apply to fish.
Compatible fish
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 6–7.5 and 24–28 °C.
They share water: pH 7–8 and 26–28 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6–7.5 and 24–28 °C.
They share water: pH 5.5–7 and 24–27 °C.
They share water: pH 6–8 and 24–26 °C.
They share water: pH 5.5–8 and 24–28 °C.
They share water: pH 6–7.5 and 25–28 °C.
They share water: pH 6–7.5 and 24–28 °C.
They share water: pH 6.5–8 and 24–26 °C.
They share water: pH 6–8 and 24–26 °C.
They share water: pH 6–7.5 and 24–25 °C.
They share water: pH 6–7.5 and 24–28 °C.
They share water: pH 6.5–7.5 and 24 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 5.5–7 and 27–28 °C.
They share water: pH 7–8 and 24–28 °C.
They share water: pH 6.5–8 and 24–28 °C.
They share water: pH 6–7.5 and 25–28 °C.
They share water: pH 6–8 and 24–28 °C.
They share water: pH 6–7.5 and 24–28 °C.
They share water: pH 6–7.5 and 24–28 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 5.5–7 and 24–28 °C.
They share water: pH 7.5–8 and 24–28 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 7.5–8 and 24–28 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 5.5–7 and 24–26 °C.
They share water: pH 5.5–6.5 and 24–27 °C.
They share water: pH 6.5–7.2 and 24–26 °C.
They share water: pH 6–7.5 and 24–26 °C.
They share water: pH 6.5–8 and 24 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 5.5–7.5 and 24–28 °C.
They share water: pH 5.5–7 and 24–28 °C.
They share water: pH 5.5–8 and 24–27 °C.
They share water: pH 5.5–7.5 and 24–28 °C.
They share water: pH 7–8 and 24–27 °C.
They share water: pH 5.5–7 and 26–28 °C.
They share water: pH 5.5–7 and 24–26 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 5.5–6.5 and 24–28 °C.
They share water: pH 5.5–7 and 24–28 °C.
They share water: pH 5.5–8 and 24–27 °C.
They share water: pH 5.5–7.5 and 24–28 °C.
They share water: pH 6–7.5 and 24–26 °C.
They share water: pH 5.5–7.5 and 24–27 °C.
They share water: pH 5.5–7.5 and 24–27 °C.
They share water: pH 7–8 and 24–28 °C.
Compatible invertebrates
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 7–8 and 24–28 °C.
They share water: pH 5.5–6.5 and 24 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5–7.5 and 24–27 °C.
They share water: pH 7–8 and 24–25 °C.
They share water: pH 7.5–8 and 24–28 °C.
They share water: pH 7–8 and 24–28 °C.
They share water: pH 7.5–8 and 26–28 °C.
They share water: pH 7–8 and 24–28 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 5.8–6.8 and 24 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 5.8–6.8 and 24 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 6.5–7.5 and 24–27 °C.
They share water: pH 7.5–8 and 27–28 °C.
They share water: pH 7–8 and 24–28 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 6.5–7.5 and 24–26 °C.
They share water: pH 7–8 and 24–28 °C.
They share water: pH 7–8 and 24–28 °C.
They share water: pH 6.5–8 and 24–28 °C.
They share water: pH 7–8 and 24–28 °C.
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They share water: pH 7–8 and 24–28 °C.
Sources
- FishBaseFroese, R. and D. Pauly. Editors. 2026. FishBase. World Wide Web electronic publication.
- Seriously FishSeriously Fish. Hemigrammus erythrozonus. Ficha de especie; consultada 2026-10.
Water: FishBase gives pH 6-8 and 5-12 dH; Seriously Fish, pH 5.5-7.5 and 2-15 dGH. The profile uses the widest range: pH 5.5-8 and dGH 2-15. Size: 3.3 cm TL in FishBase and 4 cm SL in Seriously Fish; the larger is taken.
Litres per fish and minimum tank height and depth: the profile's own judgement. Seriously Fish gives only the tank base and FishBase gives no tank sizes.
Plan your next aquarium
Is this fish right for you? Plan a suitable aquarium before setting it up.