How Big Do Neon Tetras Get: (Size Guide for Neon Fish Species)

Neon tetras are a popular choice for freshwater aquariums due to their dazzling colors and peaceful demeanor. These small, vibrant fish are known for their iridescent blue and red stripes that run along their bodies, making them a striking addition to any tank. But many newbie aquarists often wonder how big do neon tetras get in home tanks.

Typically, neon tetras grow to be around 1 to 1.5 inches long, making them one of the smallest species of tetras.

Their small size makes them suitable for smaller tanks and allows plenty of room for other fish to coexist peacefully.

Despite their diminutive size, neon tetras are active swimmers and enjoy shoaling together in groups.

lifespan of neon tetra fish

In this ultimate tetras care guide, we will examine the factors that can affect the growth of neon tetras and discuss how to properly care for and maintain these beautiful fish in your aquarium. 

How Much Room Do Neon Tetras Need?

While they are small fish, there are better approaches than simply cramming them into a tiny tank. Let’s break down how to provide them with the space they need to thrive:

General Rule of Thumb:

  • Minimum Tank Size: 10 gallons for a small school (5-6 neon tetras).
  • Recommended Tank Size: 20 gallons or larger for a larger school to accommodate tank mates.

Why Space Matters:

  • Schooling Behavior: Neon tetras feel secure and exhibit their best colors in groups. A larger tank allows them to swim freely and establish their social hierarchy.
  • Stress Reduction: Cramped quarters can lead to stress, aggression, and false neon tetra disease. Ample space keeps them happy and healthy.
  • Water Quality: Larger water volumes are more stable, and it is easier to maintain good water quality, which is crucial for neon tetras’ well-being.

Remember: Observing your neon tetras’ behavior is critical. If they seem stressed, cramped or are constantly hiding, it may be time to consider a larger tank. Providing adequate space will reward you with a vibrant, active school of neon tetras that will bring your aquarium to life!

How Big Do Neon Tetras Get in Aquarium?

How big can neon tetras get? Neon tetras only grow to about an inch and a half in length, with a signature neon stripe from the middle of their body to their belly. These fish are omnivores and can be fed various live foods, such as brine shrimp or dwarf Rasboras.

Neon Tetra Life Expectancy

Neon tetras must be kept in groups of at least six to thrive. They are schooling fish that feel most secure in the presence of their kind.

They are quite hardy, thriving in a wide range of water conditions, but prefer soft, slightly acidic water with a pH between 6.0 and 7.0. It is essential to keep up with frequent water changes and maintain proper lighting in the aquarium to prevent diseases.

Glowlight Tetra Pet Fish Species Profile

The Glowlight Tetra (Hemigrammus erythrozonus) is a freshwater fish native to the Essequibo River basin in South America. It is a popular choice for aquariums due to its vibrant colors, peaceful temperament, and ease of care, making it ideal for beginner hobbyists.


The Glowlight Tetra is a small, slender fish reaching a maximum adult size of about 1.5 inches (4 cm) in length. Their bodies are semi-transparent with a silvery-peach base color. A brilliant iridescent red-orange stripe runs horizontally along their bodies from the snout to the base of the tail, resembling a glowing filament, thus giving them their name. The dorsal fin has a similar red coloration along the leading edge, while the anal and pelvic fins are tipped with white.


Glowlight Tetras are schooling fish, meaning they thrive in groups of six or more. They are peaceful and make excellent community tank fish when housed with other peaceful fish of similar size. They will become more active in a well-planted tank with hiding places and display vibrant colors.

Habitat and Tank Requirements

Glowlight Tetras inhabit slow-moving, blackwater streams with soft, acidic water in the wild. To replicate and cycle their natural habitat in an aquarium, use a dark substrate, such as dark gravel or sand, and plenty of live plants. Driftwood and almond leaves can also be added to help create a tea-colored water effect and provide hiding places.

  • Tank size: Minimum 10 gallons for a school of 6 fish
  • Water parameters: pH: 5.5 – 7.0
  • Hardness: 5 – 15 dGH
  • Water Temperature: 72 – 82 degrees Fahrenheit (22 – 28°C)

Do Neon Tetras Need to be in Pairs?

While the idea of a pair might seem romantic, neon tetras are not fish that thrive in pairs. They are schooling fish, meaning they must be in groups to feel secure and exhibit their natural behaviors. Here’s why:

Schooling Benefits:

  • Security in Numbers: In the wild, neon tetras live in large schools as a defense mechanism against predators. This instinct remains strong in the aquarium; being in a group helps them feel safe and reduces stress.
  • Social Interaction: Neon tetras are social creatures that interact and communicate with each other. They may become bored or lonely in a pair, leading to lethargy and potential health problems.
  • Enhanced Colors: In a school, neon tetras display their most vibrant colors and engage in fascinating group movements, creating a captivating display in your aquarium.

Neon Tetra Habitat and Care

Neon tetras, or ornamental fish, are popular aquarium fish imported from South America, particularly Peru and Brazil. These small fish are best kept in schools of at least 10 to mimic their natural environment in the Amazon basin.

Neon tetras are omnivores and should be fed a varied diet, including flake food, daphnia, and freeze-dried bloodworms.

Males and females can be distinguished by the curve in the middle of the body, which is more pronounced in females. A well-cycled tank with nitrate levels below 10 dGH is essential to encourage spawning.

Neon tetras may spawn in the tank, laying eggs on plants and decorations. To prevent them from eating the eggs, it is recommended that the adults be removed after spawning. Neon tetras are peaceful fish and should be kept with other small, non-aggressive species like corys.

It is crucial to provide a good filtration system to maintain water quality, as neon tetras are sensitive to ammonia. Neon tetras have a visible, transparent adipose fin in the middle of the body.

Neon Tetra Diet and Feeding

Neon tetras are omnivores with a penchant for variety. Providing a diverse and nutritious diet is crucial to keep neon tetras in schools healthy, vibrant, and active. Here’s a closer look:

Staple Diet:

  • High-Quality Flake Food: Choose a flake food specifically formulated for tropical fish, ensuring it balances proteins, fats, and essential vitamins and minerals.
  • Micro Pellets: Small, sinking pellets provide an additional option and are ideal for ensuring all fish in the school get their share.

Variety is Key:

  • Live or Frozen Foods: Supplement the staple diet with occasional treats like daphnia, brine shrimp, or bloodworms. These provide additional protein and stimulate natural hunting behaviors.
  • Freeze-Dried Foods: A convenient alternative to live or frozen options, freeze-dried foods retain nutritional value and are readily accepted by neon tetras.

Feeding Schedule:

  • Frequency: Feed small amounts 2-3 times a day. Only offer what they can consume within a few minutes to avoid overfeeding and maintain good water quality.
  • Observation: Watch your neon tetras during feeding. Ensure all fish are getting enough food and adjust the amount as needed.

Additional Tips:

  • Variety: Rotate between different types of food to ensure a balanced intake of nutrients.
  • Quality: Choose high-quality food from reputable brands to avoid potential contaminants and ensure optimal health.
  • Soaking: Soak freeze-dried foods before feeding to prevent digestive issues.
  • Fasting: Consider a “fasting day” once a week to allow their digestive systems to rest.

A varied and nutritious diet will ensure your neon tetras maintain their vibrant colors, energy, and overall well-being.

Breeding Neon Tetras in Community Tank

Breeding neons in a community tank can be a rewarding experience, but it requires some planning.

To start, neon tetras should be kept in schools to mimic their natural habitat in the Eastern Amazon region.

It’s also essential to feed your neon tetras a balanced diet, including small foods like worms or newly hatched brine shrimp.

To produce healthy offspring, you must create the right conditions in your tank, including a well-filtered environment and regular water changes.

By following these steps and taking preventive measures against diseases, you can successfully breed neon tetras in your community tank.

How big do black neon tetras get?

Black neon tetras reach a modest adult size of 1 to 1.5 inches (2.5 to 3.8 cm), making them suitable for smaller aquariums.

How big do green neon tetras get?

Green neon tetras are small, typically only reaching around 1 inch (2.5 cm) in length, making them perfect for smaller aquariums.

How big do neon tetra fish get?

Neon tetras typically reach an adult size of 1.5 to 2.2 inches in length, with females being slightly larger than males.

How big do gold neon tetras get?

Gold neon tetras reach a similar size to regular neon tetras, growing to about 1.5 to 2 inches.

How big do cardinal tetras get?

Cardinal tetras are slightly larger than neon tetras, reaching an adult size of about 2 to 2.5 inches in length.

How big is a full-grown neon tetra?

A full-grown neon tetra typically measures about 1 inch (2.5 cm) in length, making them a small and vibrant addition to aquariums.

How many green neon tetras can you put in a 5-gallon tank?

A 5-gallon tank is too small for neon tetras. They require at least a 10-gallon tank for a small school of 5-6 fish.

How long do neon tetras live for?

With proper care, neon tetras can live for 5 to 8 years and sometimes even longer in optimal conditions.


With their vibrant colors and mesmerizing schooling behavior, Neon tetras offer a captivating addition to any freshwater aquarium. As we’ve explored, understanding their needs, from tank size and companionship to diet and care, is critical to ensuring they thrive in your care. Remember, these active little fish require more space than their small size might suggest. 

A spacious environment, ideally 20 gallons or larger, allows them to exhibit their natural schooling instincts and reduces stress. A balanced and varied diet and pristine water conditions further contribute to their well-being and longevity. Whether you’re an experienced aquarist or just starting your underwater journey, neon tetras offer a rewarding and visually stunning experience. 

Dedicating a little time and effort to understand their needs will reward you with a vibrant, healthy school that splashes the Amazonian rainforest into your home. And if you’re still wondering, “How big do neon tetras get?” Remember, these little gems typically reach a maximum size of 2.2 inches, making them perfect for smaller community aquariums. So, embark on this colorful adventure and let the neon tetras illuminate your aquatic world!

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About Me

I am the founder of, a devoted wife and mother, and an avid fish enthusiast. My aim is to assist fellow fish lovers worldwide in understanding how to properly care for and breed their pet fish.

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