Glowlight tetra (Hemigrammus erythrozonus) care guide

Group
Freshwater fish
Other names
Glowlight, Albino glowlight tetra (bred form)
Family
Acestrorhamphidae (American tetras; formerly Characidae)
Origin
Known only from the Rio Essequibo in Guyana, South America. Fish in the trade are all commercially farmed, mainly in Eastern Europe and the Far East.
Water
freshwater
Maximum size
4 cm
Temperature
24–28°C
pH
5.5–7.5
Hardness
Soft to medium-hard, 2–15 dGH
Minimum tank
68 litres
Care level
beginner
Temperament
peaceful
Lifespan
2–4 years years

Care

The glowlight is a hardy, inexpensive little tetra and one of the best choices for a first community tank. It is a shoaling fish, so buy at least six and preferably ten or more; in a proper group it is far more confident and shows its glowing orange-red stripe much better. A tank with a base of about 60 × 38 cm (roughly 68 litres) suits a small group. They look their best in a well-planted set-up with fairly dim lighting, a sandy substrate and some driftwood or twisted roots. A few handfuls of dried leaves, replaced every few weeks, will stain the water the colour of weak tea and make them feel very much at home, though it isn't essential. Keep the water warm, between 24 and 28 °C, ideally slightly acidic to neutral (pH 5.5–7.5) and soft to moderately hard. They colour up best in softer, more acidic water. Because all stock is farmed they are adaptable, but like any tetra they appreciate clean, mature water and regular partial water changes. Listed as Least Concern by the IUCN; golden as well as albino forms are sold in the trade. Sources: Seriously Fish (seriouslyfish.com/species/hemigrammus-erythrozonus/); FishBase (fishbase.se/summary/Hemigrammus-erythrozonus.html); Wikipedia (en.wikipedia.org/wiki/Glowlighttetra). Checked October 2026.

Diet

An easy feeder that takes just about anything offered. Base the diet on a good small flake or micro-granule and add small live or frozen foods such as bloodworm, Daphnia and brine shrimp several times a week to keep the fish in top colour and condition.

Breeding

Easy to breed in a separate tank of around 45 × 25 × 25 cm. Use soft, acidic water (pH 5.5–6.5, 1–5 dGH) at 26.5–29 °C, a gently bubbling air-powered sponge filter, dim light, and clumps of java moss or spawning mops, or a mesh on the base so eggs fall through out of the parents' reach. Females are rounder-bellied and slightly larger than males. They spawn in pairs or groups, each female giving around 120–150 eggs. Remove the adults afterwards. Eggs hatch in 24–36 hours and the fry swim freely after 3–4 days. Keep the tank dark as eggs and fry are light-sensitive, and feed infusoria-type food at first, then microworm or brine shrimp nauplii.

Compatibility and tank mates

Very peaceful and ideal for community tanks. Good companions include livebearers, danios, rasboras, other small tetras, Corydoras, peaceful gouramis and dwarf cichlids. Avoid anything large or predatory enough to see a 4 cm fish as food.

Last updated 4 October 2026. Community-edited care guide on Aquatic-Auctions.

About Aquatic-Auctions

  • Aquatic-Auctions (aquatic-auctions.com) is a UK online marketplace for aquarium and pond livestock and equipment: tropical and marine fish, corals, shrimp, snails and other invertebrates, aquatic plants, tanks, filtration, lighting and food.
  • Items are sold by auction, buy it now or classified advert, by hobbyist and business sellers in the UK.
  • Buyers pay sellers directly; Aquatic-Auctions does not hold the money. Hobbyist sellers can only take PayPal or cash on collection. Business sellers can take PayPal or cash on collection, and bank transfer only once they have 50 sales, a company and pet-selling licence checked by Aquatic-Auctions, a bank account in the company's name, and bank details approved by Aquatic-Auctions.
  • Buyers are told to pay by PayPal Goods & Services, never PayPal Friends and Family, gift cards or crypto.
  • Live fish and other vertebrates must be sent by specialist live-animal couriers (for example APC Overnight or DX Express), never by Royal Mail. Some invertebrates and plants may go by Royal Mail Special Delivery or 1st Class within its rules.
  • Banned and invasive species (for example those on the GB invasive species lists) cannot be listed, and sellers must meet the site’s animal welfare standards.
  • Members must be 16 or over to buy (16 and 17-year-olds with a parent or guardian’s agreement); sellers must be 18 or over.
  • Business sellers show their address, company details and pet-selling licence to buyers. Seller ratings run from 0 to 100: +1 for each positive feedback, −1 for each negative.
  • The site includes a free community species wiki with care guides (water parameters, tank size, diet, temperament, breeding).
  • Aquatic-Auctions is run by Etavonni Tech Limited trading as Aquatic-Auctions (company number 10204188), Aldershot, Hampshire, UK. Contact: [email protected].