How Many Tetra Fish In A 5-Gallon Tank?

Tetra Fish In A 5-Gallon Tank

You can find so many varieties of tetra fish that you will get puzzled while choosing them for your home tank. And not everyone can afford a large tank to keep all types of tetra together. I personally love keeping a small tank in my room with a few tetra fish swimming happily. And, what is better than a cute 5-gallon for your room? But how many tetra fish in a 5-gallon tank? I know this question can literally and figuratively give you a headache.

Well, Most of the tetra fish we can keep in a 5-gallon tank are 1.5 to 2 inches long (you can keep bigger tetra fish in the 5-gallon tank). So, If we go by the general thumb rule of 1 gallon of water for 1-inch fish, we can keep nearly 2 to 3 tetra fish in a 5-gallon tank.

Okay I know I confused you more here and don’t worry I will clear your confusion by the end of the article.

But make sure to read all the information properly and follow the instructions while setting up a 5-gallon tank for tetra fish.

With no further ado, let’s get this party started.

How Many Tetra Fish In A 5-Gallon Tank?

I don’t know where to begin but first and foremost I want to warn you about the consequences smaller tank welcomes.

Overcrowding, narrow space, injuries, pollution, etc. are always there when you plan to keep to tetra fish in a smaller tank like 5-gallon.

Now being that said, let’s keep it aside and move to the number of tetras you can keep in a 5-gallon tank.

We need to look at smaller tetra fish as we cannot accumulate bigger tetras in a tank as small as this. First you need to know how many tetra per gallon of water.

As per the general rule of thumb, you need 1 gallon of water for each inch of fish. And for schooling fish like tetras, you need to be farsighted.

So, keeping that in mind, we will only plan to keep tetras smaller than 2 inches. So, 2 gallons of water for 1 tetra fish mean you can keep 2 to 3 tetra fish in the 5-gallon tank.

The number can reach up to 7 if you keep tetras smaller than or equal to 1 inch. Tetras are schooling fish but do not overstock tetras just because you want to give them an ideal school size.

You can buy 5-gallon tank online. Just click on the link and get a tank from easily.

Types Of Tetra Fish You Can Keep In A 5-Gallon Tank

Although there are large varieties of tetra fish present, you cannot keep all of them in the 5-gallon tank. There are very few tetra fish that will adjust in such a small space.

Following tetras will adjust in a 5-gallon tank without making much fuss about it:

Neon Tetra

Neon tetras are schooling fish so I do not recommend you to keep them in a 5-gallon tank. But theoretically speaking, you can keep 3 to 4 neon tetra fish in a 5-gallon tank.

You might like to learn more about How Many Neon Tetras Should You Keep In School?

You need to keep at least 2 neon tetras together and don’t let the number go over 5 when you are keeping them in a 5-gallon tank.

Here is an article you might find interesting How Many Neon Tetras Per Gallon Of Water | Different Gallon Tanks?

Penguin Tetra

Penguin tetra is just 1.2 inches long so you can surely think of the number you can keep in a 5-gallon tank.

To be honest, if you are an experienced aquarist, then you may be able to keep a few more penguin tetra in the tank.

The ideal number of penguin tetra you can keep in a 5-gallon tank is 4 to 5. However, as I said, if you are experienced enough, then you can push the number to 7 comfortably.

Lemon Tetra

Lemon tetra is nearly 2 inches in size so you might be able to keep 2 to 3 of them in a 5-gallon tank. So not let the number exceed 5 as overcrowding can bring consequences to your tetra fish.

Being one of the most preferred tetras, lemon tetra surely will be a feather to the crown on a 5-gallon tetra tank.

Black Neon Tetra

Belonging to the group of smaller tetra fish with a 1.6-inch size, black neon tetra will be another appropriate tetra fish for a 5-gallon tank.

But be careful with the number of black neon tetra you keep in such a small space. You can keep up to 5 black neon tetras in the tank but with proper care and attention.

Ember Tetra

Here is what exactly will fit your 5-gallon tank happily. Ember tetra is less than 1 inch in size, 0.8 inches to be precise. So, 5-gallon will be quite okay for these tetras if you know how many to keep.

Do not exceed more than 7 ember tetras under any condition when it comes to petting them in a 5-gallon tank. This will ensure the proper development and activities of ember tetra fish.

Will Tetra Fish Live Happily In A 5-Gallon Tank?

No, as a matter of fact, your tetras will be stressed and depressed when you keep them in a 5-gallon tank.

The smaller confined space will make your tetra fish uncomfortable. And when they don’t feel like they have enough space to swim around, they will start to act sluggish and stop eating food after a while.

Also, if you are keeping a tetra fish alone to give it space, trust me your fish will die of loneliness before anything else.

How Can You Make Tetra Fish Live In A 5-Gallon Tank?

There are few things you can do if you really wish to get a 5-gallon tank for your tetra fish. Although other fish will live happily in the 5-gallon tank and I would recommend you to research that.

That said, here is what you can do to keep tetra fish alive and happy in a 5-gallon tank:

Set-Up And Prepare The Tetra Tank

Your tetra fish will be spending their whole life in the tank. So, make sure you make it favorable for them. Clean and cycle the tank properly before adding tetra fish to the tank.

Make sure the temperature is appropriate. Buy a reliable and branded aquarium heater and use dechlorinated water.

Hydor 25W Submersible Glass Aquarium Heater will be ideal for 5-gallon tetra fish tank.

Add An Aquarium Filter

Get a filter appropriate for a 5-gallon tank and set it up properly in the tank. Make sure it works properly and clean the water regularly.

I recommend you to use Penn Plax Cascade Submersible Aquarium Filter for tetra fish tank.

Add Substrate, Aquatic Plants, and Decorations

Tetra Fish loves planted-tank and tanks full of hiding space. So, add Aquasoil as substrate favorable for plants to grow and small rocks as decorations. Learn more about  Best Aquarium Substrate For Tetra.

Here is an article dedicated to  Aquarium Plants For Tetra Fish.

What Happens If You Over Stock A 5-Gallon Tetra Fish Tank?

First of all, Don’t. Why would you risk killing your fish by keeping them among the crowd and unhealthy life choices?

Firstly, overstocking fish in the 5-gallon tank will overcrowd the tank leaving very little space for each tetra fish.

Tetra prefers to swim happily in the tank and when you obstruct their way, they tend to get stressed. These fish will go into hiding and even get depressed after a while.

Tetra fish will feel suffocated, gasping for breath, longing for food, and weak enough to fight for food with others.

Pollution increases and the ammonia level might peak up to cause ammonia poisoning. You will end up will sick, sluggish, starved, or dead tetra fish when you overstock your 5-gallon tank.

Frequently Asked Questions

Here are answers to some FAQs you might be wondering about.

How Many Gallons Does A Tetra Need?

Since each inch of fish asks for 1 gallon of water in the tank. Most of the tetras are more than or nearly 2 inches in size, so you need to keep 2 gallons of water per tetra fish.

Tetras are schooling fish, so it is better to go for a bigger tank than 10-gallon if you are serious about fishkeeping.

How Many Neon Tetra Fish Can I Put In A 5-Gallon Tank?

You can keep up to 5 neon tetras in a 5-gallon tank but you need to be an expert in fishkeeping for that. Until then, stick with 3 to 4 neon tetra or go for a larger tank if you want your tetra fish safe.


In a nutshell, if you are keen to keep tetras, then please go for a bigger tank than 5-gallon. This tank size is not ideal for your fish to live in. That said do not exceed 3 to 4 tetras in the 5-gallon tank and make sure you give them proper care and attention.

But I will still recommend you to go for a bigger tank if you want your tetra fish to be less stressed and happy in captivity.

Good luck!!

Hope you make a decision wise enough in favor of your tetra fish.

Happy Fishkeeping!!

Recommended Articles:

  1. Top 10 Easy to Care Tetra Fish – Perfect For Beginners
  2. How Long Do Tetra Fish Live | Here Is How You Can Increase Their Lifespan

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