Neon Tetra Tank Size: Everything You Need To Know

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One question I get quite often is what is the ideal tank size for neon tetras. While neon tetras are hardy fish, that doesn’t mean they will tolerate any tank size.

In this article, I will discuss the minimum tank size for neon tetras and the ideal tank size for an average group of 6-10 individuals.

So, without further ado, let’s dive right in.

Smallest Acceptable Aquarium Size For Neon Tetras

My recommendation: Tetra Complete LED Aquarium 10 Gallons (link to Amazon)

The smallest aquarium size for neon tetras is a 10-gallon tank. This is what you should know:

  • Minimum Tank Size for a Small School: The minimum tank size for a small school of neon tetras (around 6 fish) is a 10-gallon tank.
  • Space Requirement per Tetra: Each additional tetra will require about 1-2 gallons of extra space.
  • Benefits of a Larger Tank: Choosing a tank that exceeds the bare minimum size is beneficial for multiple reasons. Larger tanks offer more room for the fish to swim, create more stable and healthier water conditions, and contribute to overall ecosystem stability.
  • Other Considerations: In addition to tank size, other considerations for keeping neon tetras should include good filtration, suitable temperature (around 70-81°F or 21-27°C), low to moderate water current, and a diet of high-quality fish food.

Also Read: Neon Tetra Tank Setup

Best Aquarium Size For Neon Tetras

My recommendation: Aqueon 20 Gallon Fish Tank Starter Kit (link to Amazon)

If you aim to keep a larger group of neon tetras, have ample space at home, are willing to invest in a tank, and want to create an extremely comfortable environment, a 20-gallon aquarium could be the ideal choice:

  • More Swimming Space: Neon tetras are active swimmers. A 20-gallon tank provides them with ample space to swim, helping to maintain their health and well-being.
  • Group Housing: Neon tetras are schooling fish and thrive in groups. A 20-gallon tank allows for a larger group of fish, which can reduce stress and promote healthy social interactions.
  • Water Quality: Larger tanks like 20-gallon ones are easier to maintain in terms of water quality. They dilute waste more effectively and have more stable temperatures, which are crucial for the sensitive neon tetra.
  • Environment Enrichment: In a 20-gallon tank, there is more room for plants, decorations, and hiding spots, which can significantly enhance the tetra’s environment. Neon tetras appreciate densely planted environments.
  • Lower Stress: Larger environments can decrease the stress on the fish, leading to better coloration and overall health. Stress in smaller tanks can lead to disease and shorter lifespan for these fish.
  • Breeding Opportunities: Larger tanks provide better opportunities for breeding. If neon tetras are given enough space, they can breed and increase their population naturally.
  • Potential for Community: A 20-gallon tank provides enough space to house other compatible species with neon tetras, creating a vibrant and diverse aquarium community.
  • Reduced Aggression: Ample space in a 20-gallon tank can help reduce territorial aggression that might occur in smaller, cramped conditions.

Also Read: Do Neon Tetras Need A Heater?

How Many Neon Tetras Can You Keep In An Aquarium?

The number of neon tetras you can keep depends on the size of your tank:

Tank SizeNumber of Neon Tetras
5-Gallon Tank3
10-Gallon Tank6-7
20-Gallon Tank10-12
30-Gallon Tank15-20
40-Gallon Tank20-25
55-Gallon Tank30-35

5-Gallon Tank

For a 5-gallon tank, you can comfortably accommodate about 3 neon tetras.

While it may seem like a small figure, it’s important to remember that neon tetras need a certain amount of space to stay healthy and thrive.

The compact environment of a 5-gallon tank offers just the right balance of space and containment for these small, vibrant fish to swim freely and thrive.

Also Read: How Many Neon Tetras In A 5-Gallon Tank?

10-Gallon Tank

When it comes to a 10-gallon tank, it provides a larger habitat, which is ideal for maintaining 6-7 neon tetras.

The increased space not only allows for a more dynamic and active school of fish but also ensures each tetra has sufficient room to explore, thereby maintaining a healthy and stress-free environment.

Also Read: How Many Neon Tetras In A 10-Gallon Tank?

20-Gallon Tank

For a 20-gallon tank, it’s suitable for approximately 10 to 12 neon tetras.

This larger volume offers an even more generous space for these energetic, colorful fish to swim and navigate.

It provides a great opportunity to create an excellent and engaging display, allowing your tetras to exhibit their natural schooling behavior.

Also Read: How Many Neon Tetras In A 20-Gallon Tank?

30-Gallon Tank

A 30-gallon tank offers a spacious environment for your neon tetras, capable of hosting between 15-20 of these shimmering creatures.

This substantial tank size presents ample room for a thriving school of neon tetras, significantly enhancing the visual appeal of your aquarium while also allowing the tetras to interact socially, which is vital for their welfare.

Also Read: How Many Neon Tetras In A 30-Gallon Tank?

40-Gallon Tank

If you have a 40-gallon tank, the number of neon tetras you can keep increases to 20-25. 

This expansive environment supports an even larger, more dynamic school of these popular, brightly colored fish.

This size of a tank allows your neon tetras to display their natural behaviors fully and ensures they have enough room to maintain their health and happiness.

Also Read: How Many Neon Tetras In A 40-Gallon Tank?

55-Gallon Tank

Lastly, in a generously-sized 55-gallon tank, it’s possible to maintain a bustling community of 30 to 35 neon tetras.

This capacious environment supports a large, lively school of tetras, creating an eye-catching spectacle in your aquarium.

The ample space ensures the neon tetras have enough room to swim and interact, contributing to their overall well-being and enhancing their vibrant display.

Also Read: How Many Neon Tetras In A 55-Gallon Tank?

Is It Suitable To Keep Neon Tetras In A Glass Bowl?

Keeping Neon Tetras in a glass bowl is generally not recommended for several reasons:

  • Limited Space: Neon Tetras are active swimmers that enjoy schooling with their species. A glass bowl usually doesn’t provide the space required for their healthy movement and social interactions.
  • Poor Water Quality: In small bowls, water quality can quickly deteriorate due to accumulation of fish waste. Neon Tetras require clean, stable water conditions, which are hard to maintain in such a limited volume.
  • Lack of Filtration: Most bowls don’t come with filtration systems. Neon Tetras, like most fish, need a good filtration system to remove waste and prevent the buildup of harmful substances.
  • Temperature Regulation: Neon Tetras are tropical fish and require a steady water temperature between 70-81°F (21-27°C). It’s challenging to maintain this in a glass bowl, which can easily become too warm or too cold due to environmental fluctuations.
  • Oxygenation Issues: Smaller water volumes in bowls often lead to insufficient oxygenation, which is essential for the health of Neon Tetras.
  • Stressful Environment: The cramped and often unstable conditions in a bowl can stress the fish, leading to a weaker immune system, loss of color, less activity, and even premature death.
  • Lack of Environmental Enrichment: Tetras prefer a tank with lots of hiding spots and plants, mimicking their natural habitat. In a glass bowl, it’s impossible to provide such an environment.
  • Risk of Jumping: Fish kept in bowls often try to jump out due to unsuitable conditions. Neon Tetras could potentially hurt themselves or even die if they jump out of the bowl.

Also Read: Do Neon Tetras Need Light?


For a quick refresher, here’s a brief roundup of the main ideas I presented earlier:

  • The minimum recommended aquarium size for neon tetras is 10 gallons, accommodating around 6 neon tetras comfortably.
  • The preferred aquarium size for neon tetras is 20 gallons, allowing for a decent number of neon tetras (up to 12) and other compatible species.
  • Following the guideline of 1 fish per gallon is reliable for stocking neon tetras.
  • Gender considerations are unnecessary when selecting neon tetras for aquarium stocking.
  • Neon tetras are social fish that should be kept in a communal environment of at least six and introduced to compatible species.
  • Glass bowls are not suitable for neon tetras and should be avoided.