Hemigrammus erythrozonus
A horizontal neon-orange stripe glows against a translucent body, like a softer, warmer version of a neon tetra. Looks spectacular against dark substrate and tannin-stained water. More peaceful than rummynose, less demanding than cardinal.
Glowlight Tetra (Hemigrammus erythrozonus) reaches 3.5–4 cm as an adult and needs a minimum tank of 60 L. Native to Essequibo River basin, Guyana, it lives in the mid water column with a peaceful temperament. Aim for 22–28 °C, pH 5.5–7.0, and 1–8 dGH hardness. Lifespan is 4–6 years with good care. Keep glowlight tetra in groups of 8+, yes schoolers need numbers to display natural behaviour. Diet: omnivore, Crushed flake, micro pellets, frozen daphnia, baby brine shrimp. Plant-safe: Yes. Shrimp-safe: Mostly (may eat shrimplets).
Care at a glance
A horizontal neon-orange stripe glows against a translucent body, like a softer, warmer version of a neon tetra. Looks spectacular against dark substrate and tannin-stained water. More peaceful than rummynose, less demanding than cardinal.
By Mike ElmiraUpdated 2 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether glowlight tetra fits in your tank.
Mid
Yes
Group of 8+
Characidae
Omnivore
Crushed flake, micro pellets, frozen daphnia, baby brine shrimp.
4–6 yrs
Medium
Quiet tannin-stained streams of Guyana
Essequibo River basin, Guyana
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Other peaceful South American tetras, corydoras, otocinclus, rams, apistogramma, dwarf gouramis (peaceful ones).
Fin-nippers, aggressive cichlids, anything large.
Hard-won lessons from the tank.
Pair with rummynose tetras for a stunning red-and-orange contrast against dark substrate. Glowlights are slightly less skittish than neons and tolerate community-tank disruption better. Buy a group of 8+ from a single source.
Genus 'Hemigrammus' = 'half-line' (referring to incomplete lateral-line scales). Species 'erythrozonus' = 'red-banded'.
What can go wrong and how to spot it.
Failure modes, in order of how dramatic the fix is.
Hardier than the common neon. Susceptible to ich during transport. Generally trouble-free in established tanks.
Often dismissed as 'less impressive than neons' — but glowlights' warmer orange-on-translucent body is uniquely striking against tannin-stained water. A group of 12+ in a planted blackwater tank looks like floating embers.
The practical routine, read top to bottom.
60 L+. Heavy planting with open mid-water swimming. Dark substrate and dim lighting bring out the glowing orange stripe. Tannins from catappa leaves enhance colour intensity.
2–3 weeks. Standard tetra care.
Where it comes from, how it behaves, and the variants you'll see at retail.
Where it lived before it came home.
Essequibo River basin in Guyana. Tannin-stained, soft, acidic blackwater with submerged vegetation and leaf litter.
Tiny crustaceans, insect larvae, micro-invertebrates.
Not threatened. Captive-bred and wild-caught from sustainable fisheries.
How they pair, reproduce, and grow.
Females slightly fuller-bodied when conditioned. Males slimmer with marginally brighter orange stripe. Subtle differences.
Egg scatterers. Soft acidic water at 26 °C, dense moss. Adults eat eggs — remove after spawning. Fry need infusoria first week.
The named cultivars and the lookalikes worth flagging.
Wild type, occasional 'long-fin' and 'golden' variants.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Glowlight Tetra (Hemigrammus erythrozonus) needs a minimum tank of 60 L. They live in the mid water column and should be kept in groups of 8+, so a longer footprint matters more than depth.
Target 22–28 °C, pH 5.5–7.0, and 1–8 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Mostly (may eat shrimplets). Plant safety: Yes.
Glowlight Tetra are omnivore. Crushed flake, micro pellets, frozen daphnia, baby brine shrimp.
On Fin & Stem's 1–5 difficulty scale this species rates 1/5. Almost unkillable, a solid first-tank choice. Breeding difficulty: medium.
Typical lifespan in a well-maintained tank is 4–6 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
