How Many Glowlight Tetras To Keep In A Tank?

How Many Glowlight Tetras To Keep In A Tank

Every fish owner has a lingering question in their mind. If you are a fish owner, you may have been torn between selecting among millions of aquarium fish to keep as pets. You want your aquarium to look beautiful but also want a fish that is easy to take care of. If you are having such a problem then the solution is simple; just buy Glowlight Tetras. Now, you might be wondering how many Glowlight Tetras you should keep in a tank. Don’t worry, this article will help you know how many Glowlight Tetras you should keep in your tank per gallon of water.

1 inch of fish requires 1 gallon of water to swim around. Glowlight Tetras grow around 2 inches, so, for each fish, you need 2 gallons of water. Glowlight Tetras are a schooling fish so keep them in a group of 10 or more. Furthermore, the aquarium décor takes 2-gallon space. So, if are a beginner and planning on buying 10 Glowlight Tetras, you need a 20-gallon tank.

Glowlight Tetras are one of the most beautiful fish that you can keep in your aquarium. Glowlight Tetras have a bright reddish-orange stripe on their body. They make the aquarium glow brightly and allure people to look at them. However, many people find it troubling to calculate the number of Tetras to keep in a tank. Worry not, because this article will guide you through this.

Attributes Of A Glowlight Tetra

Physical Features

As you might have guessed by its name, Glowlight Tetras have a Glowing stripe from their nose to the tail. Their reddish-orange stripe glows beautifully in blackwater and dim lighting. They are averagely 2 inches long. A male Glowlight Tetra is brighter and smaller than the female. Females are rounder to help in their pregnancy and males are brighter to attract the female. Nature works beautifully, doesn’t it?


Many people love to keep Glowlight Tetras for their friendly nature as these lovely fish are very social. Glowlight Tetras love the company of other non-aggressive fish. They can be kept with other friendly tank mates such as RCS, Neon Tetra, Rasboras, Gouramis, etc.

Schooling Character

Do you know what a schooling fish is? Well, Glowlight Tetra is a schooling fish. Schooling fish are the type of fish that prefer to live in groups. Seclusion from the group stresses schooling fish.

If you are planning on buying only one or a pair of Glowlight Tetras then think again. You should buy them in a group of 10 or more. Buying less than 8 or 6 can make them very stressed and their stress can cause disease to foster in your tank. Yes, even fish get stressed like humans. And yes, this stress can cause diseases. So, you should buy them in a group of 10 or more. 


Glowlight Tetras are native to backwaters of the Essequibo basin of Guyana. Glowlight Tetras thrive in blackwater and love dim places. The water in this area is acidic due to falling leaves which secrets tannins.

They prefer cool and dark shades that an aquarium plant provides. So, you should buy a décor or an aquarium plant to relieve their stress.

How Many Glowlight Tetras Should You Get?

Many Glowlight Tetra owners are confused about the number of fish they should get for their tank. Don’t worry too much because it is really simple. I will tell you an important thing and that is- the bigger the tank, the better. The greater the number of fish, the better.

Glowlight Tetras are a schooling fish. They love to stay in groups although they don’t always do that. They generally swim together when they feel threatened. Glowlight Tetras swim freely but always together with their type. So, before buying Tetras, you should think about how many you should buy.

You should buy them in a group of 10 or more. If you buy 8 or less, you are making a huge mistake. Why is buying less Glowlight Tetras a mistake? It’s because secluding your Tetras from their group will make them stressed. Stress lowers their immunity. And lower immunity means a diseased Glowlight Tetra.

For a beginner, you should get them in a group of 10 or 15 and that’s the best decision you will ever make. A bigger tank also ensures the good bacteria have a greater area to grow which maintains the nitrogen cycle.

Imagine how you feel during the quarantine. Living within the four walls of your home every single day with nothing to keep your hands busy. Boring and stressful, isn’t it? You might have indoor hobbies to pass time but that’s it. These Glowlight Tetras also feel like you do. Keeping them in a small tank will stress them. So, buy a big tank of 20 gallons and keep 10 Glowlight Tetras in your tank.

Buy 10-15 Glowlights if you are a beginner.

How Many Glowlight Tetras Should You Keep Per Gallon Of Water?

Once you know about their schooling behavior and have decided upon to keep them, you need to calculate how big of a tank you can buy, to fit your Glowlight Tetras. Although you might have trouble calculating, it is very easy if you use the rule of thumb. Read the following carefully.

1 inch of your fish requires 1 gallon of water to swim around, especially for tiny fish like Glowlight Tetras. Your fish grows 1.75-2 inches but it is better to calculate for 2 inches so your fish can have a big comfortable space to swim in. The décor like driftwood and aquarium plants will take 1-2 gallons of your tank. You need to keep your fish in a group because of their schooling character so if you are planning on buying 8 fish, 18 gallons of water are needed so that your fish has a lot of room to swim in.

If you are still confused, you can read the following to know how many fish you can fit in your tank.

How Many Glowlight Tetras In 10 Gallon Tank?

According to the calculation above, your 10-gallon tank can house 6 Glowlight Tetras. How?

Let us suppose, the average your fish grows 1.75 inches. By calculation, 10-gallon of water/1.75 inches will give you 5.7 fish which is close to 6 fish.

The décor might sometimes take 2 gallons water area. So, you can barely house 4-5 Glowlight Tetras. Your fish needs a group of a minimum of 10 to survive happily. So a 10-gallon tank is out of your buying list.

Also Read: How Many Neon Tetras in a 10-gallon tank

How Many Glowlight Tetras In 20 Gallon Tank?

20-gallon tank can house 10-11 Glowlight Tetras.

Suppose, 1 gallon is taken up by the décor. The remainder of 19 gallons is divided by 1.75 inches of fish which gives 10.85 fish, closer to 11 fish.

For a beginner, a 20-gallon tank is the best option. You should house 10 Glowlight Tetras in a 20-gallon aquarium. A 20-gallon tank is easy to clean and easy to maintain.

How Many Glowlight Tetras In 30 Gallon Tank?

A 30-gallon tank can house 16-17 Tetras.

After the décor uses 1.5 gallons of water, the remainder of 28.5-gallon water is divided by 1.75 inches of Tetras. So, you can house 16.2 Tetras. However, keeping 17 Tetras is alright.

A 30-gallon tank is recommended for experts who can handle looking after16 fish. However, if you are interested in buying a big tank and making your room bright and glowing, then a 30-gallon tank is for you.

Also Read: How Many Neon Tetras Per Gallon Of Water | Different Gallon Tanks?

What Will You Have To Deal With When You Keep Too Many Glowfish In Your Tank Per Gallon?

How do you feel during quarantine? Being locked up inside your home with nowhere to go is very depressing. Likewise, if you keep too many Glowlight Tetras without calculating the gallons of water it needs in the tank, then they will get depressed too.

Seeing lots of glowing Glowlight Tetras in a tiny tank might seem beautiful but it is a huge mistake you’re making. Glowlight Tetras like to swim in bigger spaces and they are very avid swimmers. Overcrowding will affect their health severely. This overcrowdedness creates stress and disease in your pet fish. Some may even die.

Furthermore, more fish secrete more wastes. The good bacteria will have a hard time converting toxic ammonia to nitrates. This imbalance in the nitrogen cycle will cause disease in your fish. So, you shouldn’t make the mistake of overcrowding your aquarium.

Keeping Glowlight Tetras in a larger tank with lots of aquatic plants will make them very happy. Since your fish has a large tank to swim in, your fish will be healthy and happy. So you should buy a big tank and keep the calculated number of Glowlight Tetras in your tank.

Do You Require Additional Gallons Of Water With Addition Of Tank Mates?

Glowlight Tetras are very social and they love to play with other tank mates. And you can definitely keep your Glowlight Tetras with other friendly buddies. You might think that adding some tank mates for your Glowlight Tetras without the addition of water is alright. But, this is a huge mistake you’re making.

Every fish needs its area to swim in. A small tank with limited movement will make any fish depressed. So, if you are planning on keeping tank mates with Glowlight Tetras, then you should buy a bigger tank that can fit additional gallons of water. Furthermore, a bigger tank has lots of good bacteria that convert the excess ammonia in fish wastes into good nitrates.

In your tank, add tank mates for your Glowlight Tetras but please don’t forget to add more water too. A big tank is never a problem.


I hope you have got information regarding the number of Glowlight Tetras to keep in your tank. They are a hardy fish and very easy to look after, but they need a good environment to survive in. Buying them in a group of 10 or more and keeping them in a big tank that can hold 20-gallon or more gallons of water is very important.

I hope this article helps you to calculate the number of Glowlight Tetras you can fit in your tank. With a lot of space to swim in, I’m sure they will live happily in your tank.

Image Credit: George Farmer, Flicker –

Related Articles:

  1. Glowlight Tetra’s Diet: How Often To Feed Them And Best Food?
  2. How To Breed Glowlight Tetras – Step By Step Guide
  3. Albino Glowlight Tetra – Everything You Need To Know About
  4. How Many Neon Tetras Should You Keep In School?
  5. How Many Tetra Fish Per Gallon of Water?

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top