Best Tank Size For Keeping Neon Tetra

Ideal Tank Size for Neon Tetra

Neon tetras are one of the most popular freshwater aquarium fish today. Its vivid colors, active behavior, calm temperament, and hardy nature makes it one of the most favorite choices for beginners. But sometimes people consider keeping this fish in a small tank because of its small size. If you also have the confusion regarding the best tank size for neon tetra, then you have come to the right place.

Neon tetras are shoaling fish, and they prefer to live in a group. At least 5-6 neon tetras need to be together in order to live healthily. For this bare minimum school size, a tank of 10-gallons is minimum. If you want to add the number of fishes, then you must increase water accordingly. I will discuss more regarding this minimum tank size and its importance. So let’s get started.

Minimum Tank Size For Neon Tetra

Neon tetras are small schooling fish. These fish prefer to live in a stack and are quite active. Tetras like to swim around the middle portion of the tank.

The minimum tank size for a neon tetra depends upon the number you are keeping. Any fishkeeper would suggest starting with at least 5 or 6 of them. But to get the best out of neon tetras, I recommend keeping at least 10 of them. This eliminates small tanks less than 10-gallon size.

So, a 10-gallon tank would be the bare minimum to host a small school of neon tetras. If you decide to increase the number of fish, then add at least 2 gallons of water for each fish added.

Also Read:

How Many Neon Tetras in a 10-gallon tank

How Many Tetra Fish Per Gallon of Water?

Ideal Tank Size For Neon Tetra

When it comes to fish in captivity, every fish has a minimum and ideal tank size. In a minimum tank size, a fish would just survive whereas in an ideal tank; it would live in satisfaction.

So, if you want your fish to be satisfied and have space, then always go for the ideal tank-size. In the case of neon tetras, the ideal tank size would be about 20 gallons. This 20-gallon freshwater tank should be able to host 10-13 neon tetras. A 20-gallon tank also has all the space for important decors and plants that your neon tetra will need.

In this ideal tank size, there will be no crowding issues and water chemistry disturbances. It will be easier for you to stabilize the water parameters. This tank is not only suitable for ten tetras but can also host other freshwater species. You can use this as a community tank by adding a betta or another small school of dwarf cichlids, gouramis, or barbs.

How Many Neon Tetras In A Tank?

This again depends upon the size of the tank you are using. In the minimum tank size that we recommend, i.e., 10 gallons, 5-6 neon tetra can survive with ease. However, in the ideal tank size of 20 gallons, the ideal school size of neon tetra, i.e., 10-12 fish can survive easily. Having at least ten neon tetras in a school is universally accepted as ideal for neon tetras. But if you have a bigger tank, say 40-gallon then it can easily host more fish.

I would always recommend throwing in some compatible, non-aggressive, and small fish in the tank with neon tetras. Try avoiding bigger and aggressive fish like angelfish and cichlids.

Why Should You Avoid Smaller Tank?

There is nothing right about keeping fishes in small tanks of about 5-gallons. Even the smallest of fish like neon tetras require at least 10-gallon size to be healthy. Sometimes your fish might be living in a 5-gallon tank, but you might never understand the pain, stress, and suffocation it is going through.

Also Read: How To Keep Tetra Fish Happy And Healthy

With neon tetras, if you choose anything smaller then 10-gallons, then you won’t be able to keep 5-6 fish. Keeping 5-6 neon tetras in such a tank means overcrowding. This will obstruct your fish’s ability to swim around freely. Not allowing a fish to swim properly is even worse than not feeding it or not cleaning its environment. This will eventually lead the fish to stress, and it will show unhealthy symptoms like loss of appetite and tiredness. Finally, the fish will die, and you won’t even be able to figure out why.

Also Read: How To Feed Tetra Fish Fry Properly | Dos and Don’ts With Alternative Fry Food

You might think that maybe if you reduce the school size to about 2-3, then the fish would do fine. But a small school size also creates lots of problems. A neon tetra in a small school experiences symptoms like stunted growth, infertility, heart problems, and susceptibility to disease. It will have high levels of body stress hormones. Finally, the fish will die a premature death.

 A small tank also cannot contain necessary equipment like filters, heaters, decorations, and plants. If you manage to put all these kinds of stuff, then your fish won’t have enough swimming space. So, it is best to avoid tanks smaller than 10-gallons.  

Why Do You Need A Right-Sized Tank?

This question has lots of obvious answers. A right-sized tank offers a wide range of advantages to your fish. For a neon tetras, a minimum tank of 10-gallon or an ideal tank of 20-gallon provides these benefits:

  •  Since neon tetras are active fish and like swimming around, a right-sized tank allows them to do this. In a spacious tank, neon tetras can explore and move here and there. This gives them freedom and also allows them to grow to their fullest.
  • In a right-sized tank, neon tetras can breed and multiply a lot easier than in a small tank. Neon tetras are quite difficult to breed in the home aquarium. These fish require specific water parameters to start the mating season. Usually, we recommend breeding them in a separate tank. This tank can be a bit smaller but should be at least 6-8 gallons with similar water parameters as their main tank.
  • A right-sized tank also allows you to keep plants and decorations. These things let neon tetras get away from bullies and predators if present in a tank.
  • You don’t have to worry about unstable water parameters and ammonia spikes in a right-sized tank. Usually, a small tank with lots of fish gets dirty and has fluctuating parameters. But if you have the right-sized tank, neon tetras will never die due to toxicity or chemical imbalance.
  • A right-sized tank also offers space for other fish. Neon tetras are social fish and prefer living with other species. You can add peaceful, colorful, non-aggressive, and similar-sized fishes like barbs, corydoras, rasboras, and dwarf gouramis. Neon tetras will live a better life in a community tank than in a “species-only” tank.

Also Read: The Lifespan of Neon Tetra – How Long Does a Neon Tetra Live For?

Can A Tank Be Too Big For Neon Tetra?

A tank can never be too big for any fish. But having a large tank for just a few fishes can be inefficient for the owner. It takes up unnecessary space and costs much. If you have a large tank of about 50-gallons, then you should keep fishes accordingly. In the case of neon tetras, the ideal tank is 20-gallons for ten fishes if you decide to add more fish the add up at least 2 gallons for each fish.

Can Decoration And Other Equipment Affect Tank Size?

Decorations, plants, and other equipment like filters, heaters, and lights are important assets to any aquarium. Without these kinds of stuff, your aquarium won’t be able to host your fishes comfortably. In a small tank, the presence of these things affects your fish quite a lot. But if it is a big tank then, usually filters, heaters, and light don’t take up that space. The presence of these things overshadows the fact that they displace a lot of water.

While setting up a tank, you should choose these types of equipment carefully. Today there are powerful filters available that occupy a lot less space. LED lights can lit up your tank even from outside the tank, and heaters are long cylinders that don’t take much space. So, it is fair to say that all the electrical equipment doesn’t take up much space.

But if you have big decors like solid driftwoods, rocks, and other fancy items, then it might be troublesome for many fish. So, always choose these types of stuff wisely.

Aquarium Requirements

Neon tetras are hardy fish once they are well-settled in the tank. But these fish can sometimes take a long time to comfort themselves in their new homes. Neon tetras are also quite sensitive to water parameter fluctuations like pH, temperature, and other chemical concentrations.

Adding them in a tank without cycling it, is the cruelest thing you can do to them. Neon tetra prefers a temperature of about 70°F to 81°F. Normally it is best to keep fish in neutral water with pH 7.0, but these fish can tolerate acidity up to 6.0. So, a pH of about 6-7 is optimal. Also, maintain softness in water (<10 dGH).

Also Read: Are Tetra Hardy Fish

Can You Keep Neon Tetras In A Bowl?

If you ask this to a professional fishkeeper or someone who loves fish, they might get mad. A bowl is not supposed to host any kind of fish, not even the smallest one. Although it is commercially available for the purpose of fishkeeping, I personally believe that it should be banned from the fishkeeping business.

A tetra can never swim freely in a bowl. Don’t even get me started on the water parameter fluctuations and chemical imbalance. There is nothing right about a fishbowl. It limits your filtration options, and the only way to get a clean bowl is by changing almost all of the water daily.

But if you fancy a fishbowl rather than tetras, then you can keep snails and small shrimps.

Setting Up A Neon Tetra Tank

Setting up a neon tetra tank is similar to any freshwater tank. It is a straightforward process, and even a beginner should be able to do it.

  • Since these fish are middle dwellers, the choice of the substrate doesn’t really matter. You should use gravel or pebbles according to your preference. First, carefully place the substrate at the base of the tank. Be careful because the gravel can break your glass. Spread the substrate evenly using your hand. I would recommend using dark substrate because it is quite common to their habitat.
  •  The choice of decors is what decides the quality and wellbeing of these fish. You can use plants, driftwoods, and caves for decorations. The main purpose of adding these decors is not decoration but to create hiding spots and making the tank look as dark as possible. Amazon Sword, Anubias nana, Java Fern, and java moss are some of the best live plants for their tank. In their natural habitat, plants block the natural sunlight. Their body has vivid coloring so that they can identify their fellow fish even in dark and cloudy water.
  • You can also install black driftwoods in the tank. Be sure that the presence of these decors inside your tank doesn’t obstruct the fishes’ swimming space.
  • Install lights that aren’t too bright for your fish. If you have plants, then go for heavy lights.
  • Choose filters that provide excellent filtration but doesn’t create a huge water flow. A powerhead filter with about 40GPH would be perfect for a 10-gallon tank.
  • Finally, add clean tap water.

After doing all of these things, you should cycle your tank for about 6-8 weeks. This allows important anaerobic bacteria to colonize the tank. You can use food fish and small live fish to speed up the process.

Read Full Article On: How to Set up an Aquarium for Tetra Fish – Tetra Fish Care


  • The minimum tank size for 5-6 neon tetras is 10 gallons.
  • The ideal tank size for ideal school(10-12 tetras) is about 20-gallon.
  • You should avoid small tanks and bowls at any cost.
  • Keeping neon tetras in small tanks can result in chemical imbalance and unstable water parameters. Since neon tetras are sensitive to these changes, they can die prematurely.
  • Try to create a dark impression in their tank by using lots of plants and dimming the lights. This replicates their natural habitat. You can also use a dark substrate and driftwood.
  • Right-sized aquarium keeps these fish stress-free and safe from diseases.


All in all, neon tetras are hardy fish and can live long in a right-sized tank. It is easy to care for them, but they are quite sensitive to parameter fluctuations. One easy way to maintain the right water parameters is by choosing a big aquarium.

I think I have included everything related to the best tank-size for neon tetra. I hope you will pick the right tank for your neon tetra. Any feedback and recommendations will be heartily welcomed in the comment sections below.


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