Species profile

Glowlight Tetra

Hemigrammus erythrozonus

Common names: Glowlight Tetra, Glolight Tetra

Recognized speciesTetras

Adult size

Up to 4 cm

Typical adult length 3–4 cm.

Up to 4 cm

Countries of origin

Good fit for your tank?

Good fit for

A beginner's peaceful community tank
A planted aquarium with subdued light
Mixing with other small, calm shoaling fish

Think carefully if

You plan to keep only two or three
Your tankmates are large or boisterous
The aquarium has bright light and no cover

A calm tetra from Guyana with a glowing orange-red line along a translucent body. It is widely farm-bred, hardy, and suits peaceful community tanks.

Appearance and Identification

A translucent, silvery body with a vivid orange-red to gold line from the snout to the tail, and white tips on the leading edges of the fins.

The glowing line on a clear body and the white-tipped fins identify this fish. Colour is much stronger on a dark substrate.

Mature females are rounder in the belly and tend to grow slightly larger.

Tank Requirements

Suggested filter: About 280–350 litres an hour
Suggested heater: About 75–100 W for this tank
Minimum tank volume: 70 litres
Minimum tank length: 60 cm
Minimum group size: 6
Recommended group size: 10
Activity level: Moderate
Flow preference: Low to moderate
Planting preference: Heavily planted
Hiding places: Yes
Lid recommended: Yes
Jumping risk: Low

Dark substrate, planted edges, and subdued light show this fish at its best. Leave open water for the group to swim as a shoal.

Behaviour and Tankmates

A peaceful, steady shoaling fish that is rarely aggressive or nippy.

Keep at least 6, and preferably 10 or more.

Not territorial.

Suitable with most small peaceful fish, including rasboras, corydoras, small gouramis, and dwarf cichlids. Avoid species large enough to swallow it. Very small shrimp may be eaten.

Check tankmates for this species

Water Parameters

Temperature: 24–28 °C
pH: 5.5–7.5
GH: 2–15
Stability importance: Normal

Adaptable to soft and moderately hard water. Breeding needs softer, more acidic conditions than general care does.

Parameter caveat

Most fish sold are farm-bred and more adaptable than wild stock. Acclimate slowly and use the seller's water as a starting point rather than chasing an exact number.

Feeding

Diet types: Insectivore, Omnivore
Feeding frequency: Once or twice daily
Preferred foods: Fine micro granules or crushed flakeUse a particle size the fish can swallow whole, and feed only what is eaten within a couple of minutes.
Frozen or live daphnia and cyclopsSmall crustaceans add variety and help bring adults into breeding condition.
Frozen or newly hatched brine shrimpA good small meat food a few times a week rather than the only food.

An omnivore that accepts small prepared foods and enjoys small frozen foods.

A varied diet with some frozen food keeps the colour strong.

Breeding

Breeding type: Egg Scatterer
Breeding difficulty: Moderate
Breeding temperature: 27 °C
Breeding pH: 6
Brood or egg count: Average of 120 to 150 eggs
Incubation: 1 days
Parental care: None
Baby foods: Infusoria or parameciumNeeded for the first days after fry become free-swimming, because the fry are very small.
Fine powdered fry foodUse sparingly as a supplement, and siphon out anything left uneaten.
Newly hatched brine shrimpIntroduce once the fry are large enough to swallow it, usually after several days.
MicrowormsA useful next step for fry that are still too small for brine shrimp.

Use a separate, very dim tank with fine-leaved plants or mesh over the base, with soft, acidic water at about 27 to 29 °C. Spawning can happen in pairs or a group. Remove adults once eggs appear, since they eat them. Eggs hatch in 24 to 36 hours, and fry swim freely 3 to 4 days later.

Habitat and Origin

Geographic origin: Captive Bred, Guyana, South America
Natural habitat: Blackwater, Freshwater River, Freshwater Stream
Aquarium contexts: Breeding Aquarium, Planted Aquarium
Audience level: Beginner

Classification

Profile type: Recognized species
Genus: Hemigrammus
Family: Characidae
Species group: Fish, Tetras

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Good fit for your tank?

Good fit for

Think carefully if

Appearance and Identification

Tank Requirements

Behaviour and Tankmates

Water Parameters

Feeding

Breeding

Habitat and Origin

Classification

Have you kept this species?

Other Tetras

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Head and Taillight Tetra

Hummingbird Tetra

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