How To Breed Glowlight Tetras – Step By Step Guide

How To Breed Glowlight Tetras

Have you been thinking of taking the next step as an aquarium hobbyist and breeding Glowlight Tetras? If yes, we have all the answers before you proceed with the breeding process!

Are Glowlight Tetras Easy to Breed?

The quick answer to this question is yes; they are easy to breed. In fact, even beginner aquarium hobbyists can successfully breed Glowlight Tetras.

However, although successful breeding of Glowlight Tetras in aquariums is possible, the actual process of breeding can sometimes present a few difficulties.

Learning Facts About Glowlight Tetras Before Beginning the Breeding Process

Hence, before you begin the breeding process of Glowlight Tetras, it is important to know all the relevant information that will help you successfully complete the breeding process.

Therefore, below we have information on how to differentiate their genders, how to know whether they are ready for breeding, what a pregnant Glowlight Tetra looks like, and more!

Differentiating their Genders

The key difference between a male and a female Glowlight Tetra is that the female ones have a larger and more rounded body. In contrast, male Glowlight Tetras are slimmer and generally smaller in size.

Hence, this tactic of differentiating their genders will help when you are picking out one female and one male Tetra for breeding!

Figuring Out Their Age

In order to figure out if they are old enough for breeding, the main thing to keep in mind is that all Glowlight Tetras look identical when they are young. However, as they get older and ready for breeding, the female Glowlight Tetras appear larger and have a more rounded body.

What do Pregnant Glowlight Tetras Look Like?

Although there are no telltale signs that will let you know that your Glowlight Tetras are pregnant, there are certain observations that can be made to determine whether they are pregnant.

The most obvious sign is if the Glowlight Tetra has gained mass around the abdomen and tail; this usually happens when the female Tetra is about to spawn.

When Will Glowlight Tetras Lay Eggs?

A clear sign of a Glowlight Tetra that is about to lay eggs is if the male Tetras are chasing or courting the female Tetras.

However, it is important to cover the tank to block out light when the female Tetras spawn because they can lay light-sensitive eggs.

What do Glowlight Tetra Eggs Look Like?

Glowlight Tetra eggs will be easy to spot as they are tiny clear globes that usually stick to the leaves of plants that are in the tank. However, if there is a black dot inside the egg, it simply means that the egg has been fertilized.

Furthermore, it is important to note here that Glowlight Tetras, or any Tetra fish, will not look after their eggs and will consider them food.

Hence, if you want your Glowlight Tetras to see the light of day, remove the eggs from the tank and let them hatch in a separate body of water.

How Long Does it Take for Glowlight Tetra Eggs to Hatch?

It takes about 24 hours for the eggs to hatch after the female Tetras have spawned. However, it will take the Glowlight Tetra fry a few days to start swimming freely.

Proceeding with the Breeding of Glowlight Tetras

Now that you have the general idea of what the breeding process is going to look like, we can now move on to the specifics of the procedure.

Hence, let us begin by looking at what the prepping stage of the breeding process looks like!

Step 1: Set Up Your Breeding Tank

First, you will need to get a separate tank of at least 10-gallon volume for breeding.

You will need to adjust the water parameters, place plants in the tank (ex: Guppy Grass and Java Moss), and make sure that the tank is left in darkness.

The ideal water parameters are as follows,

pH level: 5.5-7.0

Temperature: 26 – 28 degrees Celsius

Hardness: below 6dGH

Hence, once these water parameters are achieved, let the water settle for 5-6 days.

Note: Having mosquito larvae present in the tank also promotes breeding.

Step 2: Prepare your Fish Fro Breeding

The second step is to prep the fish themselves. While they are in their initial tank, not the breeding tank, feed them small portions about 3-5 times a day.

Moreover, during this period, their diet should mainly consist of high-quality flake, crumble, and freeze-dried foods. However, better results can be achieved by feeding them worms like Grindal, white, and blackworms too!

Then, once the female starts gaining mass, especially around the abdomen and tail, you can assume that it is ready to spawn.

Another obvious sign that they are ready to spawn is that the male Tetras will begin chasing/courting the female Tetras.

Step 3: Breeding Process

Hence, when the male Tetras begin chasing the female Tetras, remove them from their original tank and place them in the breeding tank with the live plants and the appropriate water parameters. Note that you will be adding the breeding fish to the breeding tank on the 6th day of preparing the breeding tank.

The next thing that will occur once the courting begins is they will both end up rolling over onto their backs, and the female expels her eggs into the water. This process, known as spawning, may take 1-2 days to start and will take place for 1-2 hours. Hence, make sure that the tank is left in darkness for this period.

Moreover, note that the Java Moss or Guppy Grass you placed while preparing the tank will now become the spawning site for the fish. This spawning site should also cover about ¾ of the total tank space.

The number of eggs expelled is usually between 50 to 500 eggs, based on the age and reproduction level of the female Glowlight Tetra.

Once the eggs have been ejected, the male Tetra will then fertilize the eggs.

However, if in case the spawning process does not take place after trying for 2-3 days, remove them from the breeding tank and pair each of them with a different Glowlight Tetra that is ready for breeding.

Although this may sound technical and tedious, the actual spawning will definitely prove to be a beautiful moment to witness!

Step 4: Removing Unfertilized Eggs

As stated earlier, once the eggs have been fertilized, you will see that there is a black dot in the midst of the egg, which is usually transparent or yellowish in color.

Hence, when the eggs have been fertilized, make sure to remove the breeding fish from the breeding tank and place them in the original tank.

This step is crucial to the breeding process as the fish do not care for their eggs and may even consume them as if they were food!

Therefore, remove the fish from the breeding tank and wait for 24 hours to let the eggs hatch. However, if you want to leave the exhausted fish in the breeding tank, you can always use a breeding mesh to keep the fish out of reach from the fertilized eggs!

Step 5: Glowlight Fry Hatch

Finally, there you have it! Your beautiful little Glowlight Tetra fry.

It is also useful to know that the fry will start resembling a Glowlight Tetra only after three weeks. This means that after about two weeks, their bodies will start showing a silver color, then at the end of week three, the trademark reddish-orange glow line will appear across their body.

Thereafter, they will look like adult Glowlight Tetras only after four months, and the females will be ready for breeding after nine months!

However, a good rule of thumb is to wait until they are a year old before letting the Glowlight Tetras breed.

How to Raise Glowlight Tetra Fry

Now that you have put in the work to let the breeding take place successfully, raising the Glowlight Tetra fry is the next step!

Related Article:
Tetra Fish Fry Care
How To Set Up Fry tank Properly
Tetra Fry Diet – What and How To Feed Tetr Fry

What to Feed Them

Once the Glowlight Tetra fry is born, it is crucial to keep certain things in mind. For instance, the food you feed the fry is essential in ensuring that they do not die.

The Glowlight Tetra fry will become free swimmers on the third day after the egg hatches. Hence, after they start swimming, feeding the Glowlight Tetra fry infusoria and paramecium cultures for the first week are the way to go. Moreover, make sure to feed them small quantities 2-3 times each day!

After the first 5-7 days, you can feed them baby brine shrimp, flake food that has been ground into a fine powder, and baby fish food to make sure that they get all the nutrients they require.

Finally, once they have grown even bigger, you can slowly introduce micro worms to their diet.

Maintaining Aquarium Conditions

It is important to note that although the breeding process itself is not too daunting, making sure that the Glowlight Tetra fry survives could prove to be more difficult. This begins from the moment the eggs have been fertilized to the time the eggs hatch, and finally until they grow to resemble adult Glowlight Tetras.

Hence, maintaining the quality of the filters, the water parameters, and other aquarium conditions is extremely important!


Breeding Glowlight Tetras is an exciting activity in itself, but seeing the Glowlight Tetra fry grow up can be even better.

They are not only pleasing to look at but are also easy to take care of. You only need to ensure that they have an abundance of live plants to hide out in as this alleviates their stress levels significantly.

Hence, as long as you make a note of the instructions provided above for breeding, you will soon have many more dazzling Glowlight Tetras swimming around in your tank!

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