Glowlight Tetra | A to Z Guide – Care, Tank Mates, Size and Diet

Glowlight Tetra

The glowlight tetra is always mistaken for the Neon and Cardinal Tetra fish. But as a fact, there are more valuable features a Glowlight can offer as much as its fish relatives!

In this guide, we will provide you some knowledge about this small but eye-pleasing species.

Read on to learn more about taking care of this fish plus— its food, tank mates, lifespan, behavior, and more. As you go along, you will understand how it is worth your every penny for that aesthetic aquarium!


Aquarists have known glowlight tetras (or Hemigrammus erythrozonus) for their adaptable nature. This fish has no much problem in varied water conditions and is great to have in community tank fishes. No wonder that it is well-known even for beginners! 

Note: Of course, even if it is easy to buy them from the store, you still need to give this fish the proper care and diet. Unlike other tetra fishes, this one has a  shorter lifespan for you to nurture.  That is why you had to provide it with the best habitat and check its water condition from time to time. 

These fish have originated from the blackwater rivers of Potaro and Essequibo, Guayana, South America. Entering the fish trade only in 1933, it has never failed to be a natural pick for aquarium enthusiasts.

Only looking from its profiles it is not hard to see why it is a favorite even for amateur owners. While you would think that you might have a hard time growing them well, worry not as these fish are hardy and manageable for your tank!


This fish has subtle differences from other tetra fish, same with their appearances.

Small and crystalline looking, the glowlight is a popular buy for the aquarium. More preferred above any tetras,  it is not only easy to care for but also is very impressive to look at in its biotope. Though it has manifestations like in the cosmic rasboras, the two are not from the same clan.

The glowlight tetra is silvery-peach in color, which is common in tetra families. The only distinct feature is its reddish-orange stripe in its body that is lining from snout to tail. The same color goes in the edge of its dorsal fin, while the rest of the fins are translucent.

There are also lucid white colors that you can spot on the fish rear and pelvic fins, in contrast to the stripe. In the dim light, this makes a beautiful show of colors. Looking at the iridescent stripe, you can also see that it looks the same as in a beaming filament of a light bulb!

Note: The glowlight rasboras are as small and glistening as the glowlight tetra. It might be hard to pick the best one from these two, but we can say that their subtle difference lies in the fins. You can notice that glowlight tetras have an adipose fin compared to the rasbora type.

Behaviour & Temperament

A small tetra, taken at near life-size magnification. The common name describes this little fish perfectly.

Glowlight tetras’ superb characteristic is their peaceful yet active behavior in tanks.

They love to be in schooling forms and frequently move at the center of the tank.  They also blend well with the other fishes you place in the water but do not risk joining them with predatory ones.   In bigger groups, they tend to swim more freely but are shyer if they are few-numbered.

The tetras are fancy to look at in groups, especially that they move as one.  If mixed with other fishes, they can do well too, as they had this peaceful character in a large milieu.

Note: It is a good idea to make the tank community diverse with other freshwater fishes. With the serene nature of the tetra fish, you may opt for those that have similar sizes and shapes as their companion. 

Try having the ones that are slow-graced and have long fins. Remember that as long as the tetra feels safe, they are active roamers and will not shy away from the front tank.

You can blend them well with minnows and other tetra fishes like the neon and cardinal tetras. Only avoid larger fishes that have an aggressive vibe for it might send your tetras into hiding. Fishes such as the angelfish are not preferable as they may see the tetras as their feed.


Glowlight tetras have short, fleeting lives. Proper care by the owner is expected for it to live and grow well in that short duration.

How long does Glowlight Tetra live?

These shimmering, tiny creatures have an average lifespan of only three to four years. Though this can be short-lived for some, the habitat contributes a great deal to longevity. 

It is best to buy them from sellers whom you trust most. This way, you can ensure that the tetras are well-cared beforehand, making them live a longer life.

With the right information in caring for the tetra fish, the owner can make its lifespan longer. Regular checking of the state and diet of the tetras can help a lot! 

Once owning a tetra fish, it is not only important to provide them with good food and water conditions. You also had to maintain alertness with the fish’s behavior, even in the slightest change in their swimming or feeding behavior.

Common Diseases

The good thing about the glowlight tetra is that it has no species-related disease to worry about. With this said, there are still common diseases that an owner should watch for with the tetra’s health.

Just like any aquarium fish, the tetras can also suffer from the same health problems. Taking proper tank maintenance can reduce any risks of terrible diseases from occurring. 

This could be (but not limited to) parasitic infections, and bacterial or fungal diseases. Take note of any early signs of ich, observed as white spots that would develop in the fish body. Prompt isolation and medication of the infected one is necessary to save the other fishes in the tank.

You can make a separate tank for the infected tetra fish and treat it until it is okay to return to the others. Again, regular assessment of the water condition is crucial for the well-being of your fish. By doing so, your fish can gain a longer life to spend in your aquarium.


The tetra fish’s small size makes them look like magical slivers in dim waters. You will love how their transparent bodies make a glittering show when they cluster together!

How big does Glowlight Tetra get?

The glowlight tetras are small, glowing fishes as their name implies. Growing only up to a length of 1.5 inches, there are a few occasions that they could even grow bigger to 2″!

It is great that they are little because as a shoaling species, they move into groups and react as a whole. And these fishes can easily do that in any standard tanks, too.

How many Glowlight Tetra can be kept together?

As tetras tend to move side by side with each other, it is advisable to have at least 6 members of them in your aquarium. A 10-gallon tank can suffice but the larger the tank, the better. 

It requires more space and water if you decide to add more members to the tetras. But note that a longer and wider tank is better for their swimming than a taller tank. 

Moreover, adding tetras will give a colorful variation to your tank of fishes. Their activeness and vibrancy will be a pleasure to look at!

Make sure that you always have the right tank for your fishes so for their comfortable roaming. Otherwise, they will gain afflicted movement or behavior in the community aquarium. 

Glowlight Tetra Care

Tank Size

An average of 10-gallon tank is good enough to cater to a half-dozen fish. For the tetra fish’s small size you can buy a standard tank for affordable prices.

Of course, if you have a larger tank, you have a fine option to still add more of this species. Tetras do love to swim in groups all the time and they are always a beautiful sight in any homey tank. 

You can add up to 10 more gallons of water for their roaming activities if you want. And mind that by doing so, you can maximize their lifespan potentials.

Tank Setup

A typical tank for your glowlight tetras can be done in a simple setting. A close imitation of the tetra fish’s habitat is always best to have, for them to thrive in the new environment.

Begin by adding the substrate of natural sand to the bottom of the tank. Mimicking the riverbeds where these little fishes come from would be a nice treat for them.

It is good to decorate the interior with relevant items for the tetras, too. Include some rocks of various sizes and also driftwood— makes perfect hiding shelters!

And what is more fascinating but to put some plants too for a realistic feel in this habitat? You may pick floating plants if you like but ensure that there is still a spacious swimming space.

Placing various plants can improve the serene ambiance of your aquarium. You can also put different heights of colorful plants for a varied effect.

Another vital part of the well-being of the fish is their exposure to healthy tannins. To provide this substance, you can either place some leaf litter or peat at the bottom of the tank. Aquarium peat is recommendable in the tank filter for it to saturate the tannins. 

Water conditions

Creating the same water settings as in the natural abode is the most ideal for the glowlight tetra. The good news is that the owner can achieve it even in the artificial resources available.

At the Guayana rivers, a scatter of leaf litter is available in all the riverbanks all year round. In the process, the waters (where the glowlight tetras originated) gain acidic properties. This event is due to the decayed fallen leaves in the rivers.

The acidic nature of their abode can be the cause why this fish is one of the hardiest in the tetra family. Still, even as a hardy fish, the tetra needs the following water requirements:

  • Water temperature: 74°F to 82°F (Best: 77)
  • Water hardness: 15 dGH max
  • pH levels: 5.5 to 7.5 (slightly acidic)

Note: Studies have claimed that replacing 20% to 25% of the water sustains its freshness and maintains a cleaner habitat for the community tank.

Diet & Feeding

Glowlight tetras are no picky eaters. They would depend a lot on whatever food you would give them— even bits of human food will do! 

What do glowlight Tetras eat?

Getting to manage glowlight tetras is an enjoyable task to do. But it does mean too that the owner must have some proper guidelines to remember while caring for them. This way, poor appetite, and parasitic conditions are not experienced by your fish.

For their daily food, consider sticking to the typical feed of micro pellets or flakes. Ordinary fish foods such as fresh brine shrimp and freeze-dried tubifex are also acceptable. Including protein in their diet is best, too.

You can serve them cod, seafood, green leafy vegetables, and even little chunks of fruit. Only beware of those fatty or oily foods as these can mess the water surface.

How often should I feed my Glowlight Tetra?

You need frequent feeding time with these fish but in light portions only. Making a minimal feeding method is a plus, as it reduces the chance of soiling the water quality. 

Overfeeding is a no-no. Remember that they do not bother picking up food that is gone at the bottom of the tank (leftovers at that).

How long can Glowlight Tetra go without food?

Like any other aquarium fish, glowlight tetras can go on for almost two days without food. But if done most of the time, this can have a negative impact on fish health.

Reportedly, the tetras can even survive within 1– 2 weeks, but ONLY if a frequent feeding is given ahead of time. On the occasion that you have to leave for several days, it is best to place plenty of fish-edible plants in the tank. By doing this, the fish has still something to munch over during your absence.

There are risks to using an automatic fish feeder if you have heard about using one. For example, problems such as food rot can occur because of condensation in the feeder. Look for a feeder only as a last resort, and inquire for the best quality. 

As a rule of thumb, feed the tetras at least 2 to 4 times a day. Sometimes you can also cut back to once a day if you have to introduce a not-so delectable feed. Also, watch out for overfeeding as excess food can cause harmful ammonium spikes in the water.

Tank Mates

Owning glowlight tetras are a good investment if you like plenty of fishes in your tank. As community fish, they are easy to blend with other species. Their calm behavior is soothing to watch with the other fishes!

What fish can live with Glowlight Tetra?

Take caution only on the size of other species that you would like to include with the tetras, as size matters too. It is better that you look for those that are as small as the tetras because bigger ones may pose a threat instead. 

Smaller fishes are okay too. Glowlight tetras do not bother having the company of other species, as long as they feel safe with them.

The following are the fit tank mates for your school of tetras:

  • Neon and cardinal tetras
  • Gouramis and the like
  • Guppies
  • Cherry Barbs
  • Catfish and loaches
  • Danios
  • Other peaceful and small fishes

What fish don’t do well with Glowlight Tetra?

Though it is tempting to buy larger fishes for diversity, this is not good for the glowlight tetras. These tetras do love to come to schools as they are small and vulnerable. If aggressive fishes are in the tank, they might see the tetras as feed.

Some of these bigger fishes you should avoid are:

  • Angelfish
  • Cichlids 
  • Any larger fish than the tetra

Investing in aquarium fishes that have similar sizes is the best choice. Containing the tank with guppies or family tetra fishes is very winsome for the glowlight tetra.


Breeding can be a bit challenging with the glowlight tetras but is at least achievable in the tank. You will see that these fish have preferences as to where they would lay eggs. Further, the eggs can only develop if they are not subject to light.

Note: A perfect spawning location for the tetra can be an isolated breeding tank full of rich leafy plants. A higher survival rate for the eggs can happen, as the tetra fish can bear more protection from other fishes.

For the sensitive eggs, use peat for the water to be darker. They can thrive in warm water that is less than 6 dGH in hardness, this also sets their early adaptation to the main tank.

Once you have selected the fish for breeding, fix the pair with protein-rich foods 2-4 times a day.

Beginning the process, prepare the tank under dim lights or place it in a darker shed for spawning. Transfer your fish with care and wait for their mating to occur. At most, 150 eggs can be expected from the adult glowlight tetra delivering within the day.

It is essential to take away the adult fish from the eggs after releasing them. Not doing so can result in the eggs getting eaten by the pair.

You also need to cultivate the eggs very well to achieve their growth. To do this, it is a standard to move the eggs away from light, as they are sensitive to it and may result in fewer hatches. Expect the egg fry to stay on their sacs for days.

Once the newly grown hatch is swimming already, you can now feed them fine flake food in gradual amounts. Introduce also the other fish food you have for the fishes to eat, including the brine shrimp.


If peaceful fishes are your thing, then glowlight tetras will not fail you. With their trademark reddish-orange stripe, they are delightful to see, particularly in groups. These fishes are always a joy to have in the aquariums. 

Is Glowlight Tetra easy to care for?

Glowlight tetras do not demand heavier maintenance than any other aquarium fishes. Originating from the blackwater rivers, the fish can thrive in substandard water conditions. 

If you are an amateur aquarium owner, you will also be glad that this is a peaceful fish, and of course, not a fin-nipper! 

Because of their community type of nature, you can add other fish species to the tank without worries. Giving them tank mates with the same behavior will create harmony in the aquarium that is good to watch.

In terms of feeding, the glowlight is not a picky eater too. They would feed on almost any type of food, even if it is human food. 

If they go in clusters, genders are also not difficult to know. The females are larger in the belly area as opposed to males, similar to most freshwater fishes.

In brief, glowlight tetra is a very manageable fish for the aquarium. Even those who lack experience in taking stead a tetra fish can find no much problem in the long run!