Tetras, with their dazzling colors and lively schooling behavior, stand as one of the most captivating and sought-after inhabitants of the freshwater aquarium world. These small, yet incredibly vibrant fish, belong to the Characidae family and are native to a variety of ecosystems ranging from the dense, vegetated waters of the Amazon basin to the clear streams of Africa. Their adaptability and relatively easy care requirements make tetras an excellent choice for both beginner and advanced aquarists looking to add a splash of color and vitality to their tanks.

The allure of tetras extends beyond their aesthetic appeal; their sociable nature and tendency to move in harmonious schools can transform an aquarium into a living, moving piece of art. This diverse group of fish includes many species, each with its unique patterns and hues, from the striking neon blue and red of the neon tetra to the subtle elegance of the black skirt tetra. The care of tetras involves considerations for their environment, diet, and companions, aiming to replicate their natural conditions as closely as possible to ensure their well-being and longevity.

Embarking on the journey of keeping tetra fish opens up a world of aquatic exploration and creativity, inviting aquarists to delve into the intricacies of aquatic ecosystems and the fascinating behaviors of these small fish. As we explore the needs, habits, and the incredible diversity of tetras, it becomes clear why they are cherished by the aquarium community worldwide.

About Tetras

Tetras are a diverse group of small to medium-sized freshwater fish belonging to the family Characidae, primarily found in the tropical and subtropical regions of South America, Central America, and Africa. Known for their vibrant colors and dynamic schooling behavior, tetras have become one of the most popular choices for aquarium enthusiasts worldwide.

The term “tetra” originates from the Greek word “tetra,” meaning four, which refers to a distinguishing characteristic of most tetra species: the presence of a fourth, adipose fin located between the dorsal and caudal fins. This small, often fleshy fin sets tetras apart from many other fish, although not all species possess it.

Tetra fish vary widely in color, size, and shape, but they share common traits that make them well-suited to life in a community aquarium. They are generally peaceful, hardy, and adapt well to a range of water conditions, making them ideal for both novice and experienced aquarists. Tetras typically range in size from about 1 to 2.5 inches (2.5 to 6.4 cm) in length, with some species growing slightly larger.

One of the most fascinating aspects of tetras is their schooling behavior. In the wild, tetras form large groups as a defense mechanism against predators, and this behavior is also observed in the aquarium. A school of tetras swimming in unison is not only a strategy for survival but also a captivating sight that adds dynamism and beauty to any tank.

Regarding habitat, tetra fish originate from various freshwater environments, including clear streams, rivers, and floodplain forests. Their natural habitats are often densely planted with ample hiding spots and soft, acidic water, which aquarists try to replicate in the home aquarium to keep their tetras happy and healthy.

Diet-wise, tetras are omnivorous, and in the wild, they feed on small invertebrates, plant matter, and detritus. In the aquarium, they are not picky eaters and will generally accept a wide variety of foods, including flake, frozen, and live foods, making their dietary needs relatively easy to meet.

The combination of their striking appearance, engaging behavior, and relative ease of care has cemented tetras’ place as a staple in the freshwater aquarium hobby. Whether drawn to the neon glow of the neon tetra, the elegant simplicity of the black neon tetra, or the vibrant hues of the cardinal tetra, there’s a tetra species to captivate every aquarist’s heart.

Tetras – All You Need to Know About Tetra Fish
Tetras – All You Need to Know About Tetra Fish

Popular Types of Tetra Fish

Tetra fish are celebrated for their diversity and vibrant colors, making them a mainstay in freshwater aquaria. Here’s a closer look at some popular tetra species, highlighting their unique features, behaviors, and habitat preferences:

Neon Tetra (Paracheirodon innesi)

  • DescriptionNeon tetras are small, brightly colored fish with a striking blue line that runs laterally along the body and a red stripe that begins mid-body and extends to the tail. They typically grow up to 1.5 inches (4,5 cm) long.
  • Behavior: Peaceful and schooling by nature, neon tetras thrive in groups of six or more, displaying their best colors and behaviors when comfortably shoaled.
  • Habitat Preferences: They prefer soft, slightly acidic water and a densely planted tank that mimics their Amazon River basin origin, with dim lighting and plenty of hiding spots.

Cardinal Tetra (Paracheirodon axelrodi)

  • Description: Similar to the neon tetra but with more vibrant colors, the cardinal tetra‘s blue and red stripes extend the entire length of the body. They grow to about the same size as neon tetras.
  • Behavior: Cardinal tetras are also peaceful and enjoy being in schools. They are a bit more sensitive to water conditions than neon tetras.
  • Habitat Preferences: Like neons, they thrive in soft, acidic water and a well-planted environment that resembles their native South American habitats.

Glowlight Tetra (Hemigrammus erythrozonus)

  • DescriptionGlowlight tetras have a translucent body with a distinctive horizontal orange-red stripe running from the nose through the eye to the base of the tail fin. They grow up to 1.5 inches (4,5 cm).
  • Behavior: Peaceful and schooling, glowlight tetras are best kept in groups and are known for their timid nature.
  • Habitat Preferences: They prefer a tank setup similar to neon and cardinal tetras, with soft, acidic water and plenty of plant cover.

Black Skirt Tetra (Gymnocorymbus ternetzi)

  • DescriptionBlack skirt tetras are known for their unique finnage and coloration, featuring a tall, black body with (sometimes long, flowing) black and white fins. They can grow up to 2.5 inches (6,5 cm).
  • Behavior: While generally peaceful, they can be fin nippers if not kept in a sufficiently large school or if housed with long-finned tank mates.
  • Habitat Preferences: They are adaptable to a variety of water conditions but prefer a setup with open swimming spaces and some dense plantings.

Congo Tetra (Phenacogrammus interruptus)

  • DescriptionCongo tetras are larger and more colorful, with males showcasing a rainbow of iridescent colors and long, flowing fins. They typically grow up to 3 inches (7,5 cm) in length.
  • Behavior: A peaceful and schooling species, Congo tetras show their best colors and behaviors in a spacious tank with a group of their kind.
  • Habitat Preferences: They prefer slightly alkaline to neutral water and a well-planted aquarium with open areas for swimming.

Additional Species

  • Ember Tetra (Hyphessobrycon amandae): Small with a vibrant orange-red color, ideal for nano tanks and prefers soft, acidic water.
  • Rummy Nose Tetra (Hemigrammus rhodostomus): Known for its bright red nose and horizontal stripe, the rummy nose tetra prefers well-oxygenated water and a strong current.
  • Serpae Tetra (Hyphessobrycon eques): Features a deep red color with a distinctive black spot on the dorsal fin, known for being slightly more aggressive than other tetras.

Each tetra species has its unique charm and requirements, but a common theme is their preference for school life, which helps replicate their natural social structure and reduces stress. When setting up an aquarium for tetras, consider their natural habitat—soft, acidic water and a densely planted environment are usually preferred. By catering to these preferences, aquarists can enjoy the full spectrum of behaviors and colors these delightful fish have to offer.

Tank Mates

When selecting tank mates for tetra fish, it’s important to consider several factors to ensure a harmonious aquarium environment. Tetras are generally peaceful fish that do well in community tanks, but their small size, schooling behavior, and specific water condition preferences dictate careful selection of compatible species. Here are key considerations for choosing tank mates for tetras:


  • Peaceful Nature: Choose tank mates that share the tetras’ peaceful demeanor to avoid stress and aggression. Aggressive or overly boisterous fish can intimidate tetras, causing them to hide or become stressed.
  • Fin Nipping: Avoid species known for fin nipping, as tetras, with their sometimes long and flowing fins (in the case of certain species), can become targets.

Size and Compatibility

  • Similar Size: Opt for fish of a similar size to prevent larger fish from bullying or attempting to eat the smaller tetras.
  • Community Compatibility: Select species that are known to live well in community tanks and have a history of being good companions to tetras.

Water Parameters

  • Matching Water Conditions: Ensure that the chosen tank mates thrive under similar water conditions as tetras (e.g., temperature, pH, hardness). Tetras usually prefer soft, slightly acidic to neutral water.
  • Stable Environment: Choose fish that require similar water quality and cleanliness. Sudden changes in conditions that might suit one species could be detrimental to another.

Activity Level and Behavior

  • Schooling Behavior: Since tetras are schooling fish, they do well with other species that have a peaceful schooling or shoaling nature. This creates a dynamic but harmonious tank environment.
  • Territoriality: Avoid overly territorial species that might claim large areas of the tank, leaving little room for tetras to swim freely.

Habitat Preferences

  • Similar Habitat Needs: Fish that require similar environments (e.g., plenty of plants, hiding spots, and open swimming areas) are usually good companions for tetras.
  • Vertical Space Usage: Consider species that occupy different levels of the tank to maximize space and reduce competition for territory. For example, bottom-dwellers like Corydoras catfish can complement the mid-to-upper level swimming patterns of tetras.

Examples of Good Tank Mates for Tetras

  • Other Tetra Species: Mixing different tetra species can create a vibrant and active community.
  • Livebearers: Such as guppies, mollies, and platies, provided their water parameter requirements align.
  • Corydoras Catfish: Peaceful bottom-dwellers that keep to themselves.
  • Dwarf Gouramis: Peaceful surface dwellers that add color and diversity without posing a threat to tetras.
  • Rasboras: Similar in size and temperament, making them excellent companions.
  • Small Plecos: Peaceful and occupy a different tank region, but ensure the species chosen doesn’t grow too large.


Always research each species thoroughly before introduction to the tank. Even within generally compatible groups, individual temperaments and health conditions can lead to unexpected interactions. Introducing new fish gradually and monitoring their behavior towards each other is crucial for maintaining a peaceful community aquarium.

Tank Setup

Setting up a tank for tetras involves creating an environment that closely mimics their natural habitat, ensuring their health, comfort, and vibrant colors. Here’s a step-by-step guide to setting up an ideal tank for tetras:

Choose the Right Tank Size

  • Start with at least a 20-gallon tank (80 liters) to provide ample space for a school of tetras to swim freely. Larger tanks are more stable in terms of water quality and allow for more complex environments.

Water Conditions

  • Temperature: Maintain the water temperature between 72°F to 80°F (22°C to 27°C), depending on the specific tetra species.
  • pH Level: Aim for a slightly acidic to neutral pH, around 5.5 to 7.5.
  • Water Hardness: Soft to moderately hard water is preferable.

Filtration and Aeration

  • Install a reliable filtration system that can keep the water clean without creating excessively strong currents, as tetras prefer gentle water flow.
  • Ensure the tank is well-oxygenated; a filter with a good turnover rate typically provides sufficient aeration.

Substrate and Decor

  • Substrate: Use fine gravel or sand that mimics the natural riverbeds of their habitat.
  • Plants: Add live plants such as Java fern, Anubias, and Amazon swords to provide hiding spots and replicate natural cover. Plants also help maintain water quality.
  • Decor: Include driftwood, rocks, and caves to create a diverse landscape and more hiding places.


  • Provide moderate lighting to mimic their natural environment, which is often shaded by canopy cover in the wild. Too much light can cause stress and promote excessive algae growth.

Tank Setup

  • Schooling Nature: Tetras thrive in groups, so plan for a school of at least 6-10 individuals, depending on the tank size. This will reduce stress and promote natural behavior.
  • Community Considerations: If planning a community tank, ensure all inhabitants have compatible temperature, pH, and hardness requirements.

Cycling the Tank

  • Before introducing tetras, cycle the tank to establish beneficial bacteria. This process typically takes a few weeks and involves monitoring ammonia, nitrite, and nitrate levels until the tank can safely convert toxins.


  • Water Changes: Perform regular water changes, about 20-25% every two weeks, to maintain water quality.
  • Testing: Regularly test the water parameters to ensure they remain within the ideal range for tetras.
  • Cleaning: Keep the substrate clean and remove any decaying plant matter to prevent ammonia spikes.

Creating a well-planned environment that caters to the needs of tetras can lead to a thriving aquarium where these colorful fish can exhibit their natural behaviors and vibrant colors. Remember, the key to a successful tetra tank lies in maintaining stable water conditions, providing ample hiding and swimming spaces, and ensuring a peaceful community setup.

Diet and Feeding

A proper diet is crucial for maintaining the health, color, and vitality of tetras. These small, active fish require a balanced diet that caters to their omnivorous nature. Here’s how to ensure your tetras are well-fed and nourished:

Variety is Key

  • Staple Diet: High-quality flake food or micro pellets form the basis of a tetra’s diet, providing essential nutrients.
  • Live Foods: Supplement with live foods such as brine shrimp, daphnia, and bloodworms to encourage natural feeding behavior and provide protein.
  • Frozen Foods: Frozen varieties of the above live foods are a convenient alternative, offering similar nutritional benefits.
  • Vegetable Matter: Include blanched vegetables or spirulina-based foods to provide necessary plant-based nutrients.

Feeding Frequency and Amount

  • Frequency: Feed tetras small amounts 2-3 times a day, only as much as they can consume in 3 minutes to avoid overfeeding.
  • Overfeeding Concerns: Excess food can decay in the tank, leading to poor water quality and health issues for the fish.

Special Considerations

  • Juveniles: Young tetras may require more frequent feedings of high-protein foods to support their growth.
  • Observation: Regularly observe your tetras during feeding to ensure they are all getting enough food and to check for any signs of illness or stress.
  • Dietary Adjustments: Be prepared to adjust the diet based on the health, activity level, and coloration of your tetras. If they appear dull or lethargic, they may need more varied or nutritious food.

Tips for Healthy Feeding

  • Rotation: Rotate different types of food to ensure a balanced diet and to keep the tetras interested in their meals.
  • Tank Environment: Ensure the tank environment, including water quality and temperature, is optimal for feeding. Stressed or uncomfortable fish may not eat properly.

Observing Your Tetras

  • Pay attention to how your tetras eat and their behavior afterward. Healthy tetras should be eager at feeding times and active. Changes in these behaviors can be early signs of health issues.

By providing a varied and balanced diet, you can help ensure your tetra fish remain healthy, active, and vibrant. Remember, the quality of the diet directly affects the health and longevity of your fish, so investing in good nutrition is investing in the well-being of your aquarium.

Tetras – All You Need to Know About Tetra Fish
Tetras – All You Need to Know About Tetra Fish

Aquascaping Ideas

Aquascaping for an aquarium with tetra fish should aim to recreate aspects of their natural habitat, which is often densely planted with areas of both shadow and light, mimicking the under-canopy streams of the Amazon and other tropical regions. Here are some aquascaping ideas tailored for tetras, designed to satisfy their need for shelter, while also creating a visually appealing display:

Amazon Biotope

  • Concept: Mimic the natural environment of the Amazon basin. Use soft, acidic water and include driftwood, leaf litter, and floating plants to create shaded areas.
  • Plants: Add species native to their habitat, like Amazon sword (Echinodorus spp.), Cabomba, and floating plants such as Amazon frogbit (Limnobium laevigatum).
  • Substrate: Use a dark, fine substrate to simulate the riverbed and help highlight the colors of your tetras.

Riverbank Scene

  • Concept: Create a dynamic layout that simulates a riverbank, with a flow of water represented by the layout of plants and substrate.
  • Plants: Use tall plants like Vallisneria or Jungle Val in the background to simulate bank vegetation, and shorter plants like Anubias and Cryptocoryne in the foreground.
  • Features: Incorporate smooth river stones and driftwood to create a natural flow and provide hiding spots.

Forest Underbrush

  • Concept: This design focuses on replicating the dense vegetation found on the forest floor, offering plenty of hiding spaces and a dimly lit environment.
  • Plants: Dense plantings of ferns, such as Java fern (Microsorum pteropus), and mosses like Java moss (Taxiphyllum barbieri) can create a lush, green landscape.
  • Features: Use driftwood to create a tangled, root-like appearance, and add leaf litter to enhance the forest floor feel.

Island Centerpiece

  • Concept: Build an island of dense vegetation in the center of the tank, surrounded by open swimming space for the tetras to school.
  • Plants: Use a mix of tall background plants and shorter, bushy plants to create the island. Mosses can be added to the centerpiece for added texture.
  • Substrate and Hardscape: Elevate the central area with a higher substrate level or a large piece of driftwood, surrounded by finer gravel or sand.

Planted Jungle

  • Concept: Aim for a wild, overgrown look with a variety of plant species, heights, and textures, simulating a jungle environment.
  • Plants: Mix fast-growing species with slower-growing, broad-leaved plants for diversity. Floating plants can be used to dapple the light, creating a dynamic lighting effect.
  • Hardscape: Include a variety of woods and rocks, positioned to look as if they were naturally deposited by water flow.

General Tips for Aquascaping for Tetras

  • Lighting: Use lighting to create areas of shadow and brightness, mimicking natural light filtering through canopy leaves.
  • Water Movement: While tetras prefer gentle water flow, incorporating areas of stronger flow can add to the naturalistic feel and help keep the water oxygenated.
  • Open Swimming Spaces: Despite the dense planting, ensure there are open areas for tetras to swim freely, as they are active swimmers and enjoy schooling in open water.
  • Maintenance: While aiming for a natural look, regular maintenance is crucial to prevent overgrowth that could impact water quality and fish health.

Creating a naturalistic aquascape not only provides a healthy and stimulating environment for tetras but also makes for a stunning visual display in your home.


In conclusion, tetras offer a kaleidoscope of color and activity to the freshwater aquarium, appealing to both novice and seasoned aquarists alike. Their care, encompassing aspects from tank setup and water conditions to diet and compatible tank mates, highlights the importance of mimicking their natural habitat to ensure their health and vibrancy. Aquascaping for tetra fish not only serves the practical purpose of creating a suitable and stimulating environment for these small, dynamic fish but also allows aquarists to engage creatively with their aquariums, crafting underwater landscapes that are both beautiful and beneficial.

By understanding the needs and behaviors of tetras, aquarists can successfully integrate these charming fish into diverse aquatic communities, where they can thrive and display their full behavioral and color potential. The key to success lies in attention to detail—providing a balanced diet, maintaining stable water conditions, and creating a tank environment that caters to the natural instincts of tetras to school and explore.

Whether drawn to the glowing hues of the neon tetra, the striking colors of the cardinal tetra, or the subtle elegance of the black skirt tetra, enthusiasts have the opportunity to create a thriving underwater community that mirrors the complexity and beauty of natural ecosystems. Tetras remind us of the joy and responsibility that comes with keeping aquatic life, encouraging a deeper appreciation for the natural world and the intricate connections within it.