Glowlight Tetra
Hemigrammus erythrozonus
Also known as Glowlight
Edited by Ivan F. · Reviewed
Beginner verdict
One of the best tetras for a general community, lively and adaptable with a glowing orange line along its side. It gets along with most livebearers, rasboras, corydoras and dwarf cichlids. Keep a good-sized group in a planted tank and it rewards you with calm, steady color.
Care at a glance
- Min tank size
- 18 US gal
- Footprint
- 24 x 15 in
- Temperature
- 75–82 °F
- pH
- 5.5–7.5
- Hardness
- 2–15 dGH
- Swim zone
- Mid-Water
- Min group
- 6 or more
- Lifespan
- Not well documented
Glowlight Tetra tank mates and swim zone
Mid-Water
Spends most of its time in this part of the tank.
Poecilia reticulata
Poecilia wingei
Xiphophorus maculatus
Poecilia sphenops
Trichogaster chuna
Trichogaster lalius
Paracheirodon innesi
Their temperature ranges barely overlap, so you will have little room for error.
Danio rerio
Their temperature ranges barely overlap, so you will have little room for error.
Barbodes semifasciolatus
Their temperature ranges barely overlap, so you will have little room for error.
Betta splendens
Betta often does best alone. Only try this in a larger, planted tank, and watch closely.
Tanichthys albonubes
Their temperature ranges do not overlap, so one of them would always be stressed.
Xiphophorus hellerii
Swordtail is big enough to eat or bully a fish as small as Glowlight Tetra.
Carassius auratus
Goldfish suit cooler water and are not suited to tropical tanks, so Glowlight Tetra is a poor match.
Trichopodus trichopterus
Blue Gourami is big enough to eat or bully a fish as small as Glowlight Tetra.
Glowlight Tetra feeding and care
How to feed
- Feed flakes or small pellets, which it takes readily.
- Add frozen bloodworm or daphnia for the best color and condition.
- Feed small portions you can see finished within a couple of minutes, because overfeeding fouls the water fast.
Telling males from females
Mature females are rounder in the belly than males and tend to grow a little larger.
Glowlight Tetra care mistakes to avoid
- Do not buy just one or two. Keep at least 6 fish so they feel secure.
- Keep it warm. It wants warmer water than some cooler-water community fish.
- Do not mix it with fish large enough to see it as food.
- Avoid bright, bare tanks. Plants and a dark substrate make its glow far stronger.
- Check your tank before you buy. Our sourced minimum is 18 US gallons.
Glowlight Tetra tank setup
A forgiving setup with room for a small community.
TankAt least 18 US gal (68 L), 60 x 38 cm
The smallest tank our sources give for Glowlight Tetra. We list only tanks that hold this volume (allowing 10%, so a standard size counts) and have at least this much floor.
None of the tanks we recommend is big enough for this species yet. See Best 20-Gallon Fish Tank: 20 Long or 29? for what to look for.
Starter kitA kit with the tank, filter and light in one box
We list only kits whose tank fits Glowlight Tetra, up to twice its minimum volume. A kit whose heater has a fixed setting shows only when that setting is inside Glowlight Tetra's temperature range.
None of our picks for the US suits this species. The options below are for Spain, and we have not confirmed that they are sold in the US.
Tetra Starter Line LED Aquarium 80 L Spain
Heater preset to 25 °C
Why we chose these (Best Aquarium Starter Kit: What to Look For). Nobody here has used or tested them.
FilterHang-on-back or large sponge filter
Easy to maintain and strong enough for a community without blasting the fish.
Seachem Tidal 55 Power Filter US
Marineland Penguin PRO 175 Power Filter US
Eheim LiBERTY 130 Hang-on Filter Spain
Seachem Tidal 35 Power Filter Spain
Why we chose these (Best Filter for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
HeaterKeep it at 75–82 °F (24–28 °C)
Adjustable heater, about 5 W per gallon: 100 W at 20 gallons, about 150 W at 29. Enough power to hold a stable temperature in most homes. Size up for a cold room.
Aqueon Pro Adjustable Heater 100 W US
Aqueon Submersible Glass Heater 100 W US
Eheim Thermocontrol e 100 Heater Spain
Tetra HT 100 Electronic Heater Spain
Why we chose these (Best Heater for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
Water conditionerDechlorinator such as Seachem Prime
Tap water contains chlorine or chloramine that harms fish.
Seachem Prime US
Fritz Complete Water Conditioner US
API Betta Water Conditioner US
sera aquatan Spain
Tetra AquaSafe Spain
Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es · Maker's details
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test kitLiquid kit such as API Freshwater Master
Tracks ammonia, nitrite, nitrate and pH while the tank cycles.
API Freshwater Master Test Kit US
API General & Carbonate Hardness Test Kit US
See it at The Shrimp Farm (a retailer; affiliate link) · Sold at Bulk Reef Supply · Maker's details
sera aqua-test box (Cl) Spain
JBL PROAQUATEST COMBISET Plus NH4 Spain
Why we chose these (Best Test Kit for a Freshwater Aquarium). Nobody here has used or tested them.
SubstrateAdaptable and does well in most tanks; river sand suits a natural-style setup.
We are still choosing products for this.
Hiding places and decorLooks best heavily planted; driftwood and dried leaves complete a natural setup.
We are still choosing products for this.
PlantsSafe with live plants
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.
Where to buy Glowlight Tetra
We have not found a store that sells Glowlight Tetra under its scientific name yet. We add stores as we confirm them.
Live animals and plants travel by courier. Check the store's live-arrival guarantee, and only buy once your tank has cycled (see how to cycle a fish tank).
Some US states restrict certain species. Check our US state aquarium rules table and your state's own rules before you buy.
Glowlight Tetra FAQ
What size tank do Glowlight Tetras need?
Our sourced minimum is 18 US gallons (68 liters), with a footprint of 60 x 38 cm. A bigger tank is always easier to keep stable.
How many Glowlight Tetras should I keep?
Keep at least 6 fish. Bigger groups usually look better and behave more confidently.
What can live with Glowlight Tetras?
Good matches on our list include Fancy Guppy, Endler's Livebearer and Platy. Avoid White Cloud Mountain Minnow and Swordtail.
How long do Glowlight Tetras live?
Lifespan is not well documented for this species. Stable water and a good diet help any animal live longer.
Are glowlight tetras good for beginners?
Yes. Because they are bred commercially in huge numbers, they adapt well to most well-kept tanks and get along with most peaceful fish.
Glowlight Tetra facts and sources
- Family
- Characidae
- Native to
- Essequibo River, Guyana
- Adult size
- 1.6 in (4 cm)
- Temperament
- Peaceful
- Social needs
- Schooling/Shoaling (6+)
- Diet
- Omnivore
- Water flow
- Gentle
- Substrate
- Any
- Live plants
- Yes - Loves Plants
- Shrimp
- Adult Shrimp Only
- Fin nipping
- None
- Vulnerable to nippers
- No
- Breeding
- Moderate
Sources
- Seriously Fish: Tank size, water ranges and behavior
- FishBase: Cross-check of water ranges and size
Lifespans are approximate and come from aquarium care guides, because these databases rarely publish them.
Where sources differ, we show the Seriously Fish aquarium figures.
Spotted something wrong? Report a parameter correction. For a sick fish, see our veterinary disclaimer.