Diamond Tetra 101: Species Facts and Care Guide

diamond tetra
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Last Updated: May 11, 2023 by Flora Gibbins

Ah, the Diamond Tetra, a true under-the-sea treasure!

There’s something truly magical about this radiant little creature that outshines all others in a freshwater aquarium. Imagine this – a fish that glistens like a precious gem, earning its name from the diamond-like sparkle it exudes when light hits it just right.

Did you know that Diamond Tetras are known to produce a natural fluorescent pigment that makes them glow under black light? Yes, you read that right, these tetras can light up your aquarium like a mini rave party!

But there’s more to these beautiful fish than just their shining scales. I’ve helped some friends dip their toes in fishkeeping with these little guys, and I must say that they are a treat to watch, as well as hardy and easy to care for, making them a great choice for beginner aquarists.

Let’s dive deeper into the world of this glimmering fish, we’ll discover more about their unique features and what it takes to provide them with the perfect environment to shine their brightest.

Diamond Tetra Facts and Overview

  • Common Names: Diamond Tetra, Pittier’s Tetra, Diamond Characin
  • Scientific Name: Moenkhausia pittieri
  • Adult Size: 2-2.5 inches (5-6 cm)
  • Average Diamond Tetra Lifespan: 5-7 years
  • Colors and Markings: Distinct diamond-shaped pattern on their body that shimmers in different shades of silver and gold
  • Origin: Lake Valencia in Venezuela, and nearby rivers in South America

Origin and Distribution

The enchanting Diamond Tetra, known in scientific circles as Moenkhausia pittieri, is a freshwater fish that originates from the waters of Venezuela, specifically the Lake Valencia Basin and the Carabobo region in South America. These peaceful fish thrive in slow-moving rivers, streams, and floodplains, surrounded by dense vegetation and a substrate of leaf litter, which provides them with a perfect environment to flourish.

In their natural habitat, Diamond Tetra fish typically swim in large schools, using their shining scales to communicate with each other and to intimidate predators. These fish are omnivores and feed on small insects, crustaceans, and algae found in their surroundings.

Diamond Tetras were first introduced to the aquarium hobby in the 1950s quickly captured the hearts of fish enthusiasts worldwide. Their striking appearance and peaceful demeanor made them an ideal choice for community tanks, and their adaptability to various water conditions allowed them to thrive in the aquarium setting.


One of the standout features of Diamond Tetras is their unique diamond-shaped pattern that shimmers in different shades of silver and gold. When the light catches their scales just right, they look like they’re covered in tiny diamonds, which is where their name comes from.

I always enjoy watching them swim around and observing their distinct colors and patterns. They have a sleek, streamlined body shape with a forked tail fin and a slightly upturned mouth that gives them a playful and curious expression.

Males are generally more colorful and have longer fins than females. In addition to their diamond pattern, they also have a distinct red stripe running horizontally across their body that adds to their overall visual appeal.

One thing to note is that Diamond Tetras may lose some of their coloration if they are stressed or not kept in optimal water conditions. So, it’s important to maintain a clean and healthy tank environment to keep your fish looking their best.

Behavior and Temperament

Diamond Tetras are known for their peaceful and social nature, making them great additions to community aquariums. They are active swimmers and love to explore their surroundings, so it’s important to provide them with plenty of space to move around.

In my experience, Diamond Tetras are also playful and curious fish. They are not timid and will readily investigate new objects or changes in their environment. They tend to be more active during the daytime, and their shimmering scales make for a beautiful sight as they swim around the tank.

They are schooling fish, and they should be kept in groups of at least six other fish of the species to allow them to exhibit their natural schooling behavior. Keeping them in smaller groups or as solitary fish can result in stress and health issues.

Although the Diamond Tetra species is generally peaceful, some may occasionally display territorial behavior towards their own species, particularly during breeding. It’s important to provide your fish with plenty of hiding spots and plants to establish their own territories and minimize aggression.

diamond tetra school

Diamond Tetra Tank Mates

One of the joys of keeping Diamond Tetra in your tank is their ability to coexist peacefully with a variety of tank mates. Here are some other fish that can live in the same tank with them:

Compatible Freshwater Fish Species

  • Corydoras Catfish: These bottom-dwelling fish are peaceful and social, just like Diamond Tetras. They also help keep the tank clean by scavenging for food scraps.
  • Neon Tetras: These colorful fish are a popular choice for community aquariums and can coexist well with Diamond Tetras. They have similar water requirements and are non-aggressive.
  • Guppies: These small, active freshwater fish are another great choice for community tanks. They are easy to care for and come in a variety of colors and patterns.

Keep in mind that these are schooling fish, so they’ll feel more comfortable in a group of at least six of their own kind.

Non-Fish Tank Mates

  • Ghost Shrimp: These small, transparent shrimp are peaceful and can help keep the tank clean by eating algae and other debris.
  • Snails: There are many types of snails that can coexist with Diamond Tetras, such as Nerite and Mystery Snails. They also help keep the tank clean by eating algae and uneaten food.

Tank Mates to Avoid

Although Diamond Tetra fish are relatively peaceful, they may not fare well with more aggressive or larger fish that may see them as food.

  • Large, aggressive fish: Fish species such as Cichlids, Oscars, and Bettas should be avoided as they may bully or stress out Diamond Tetras.
  • Bottom-dwelling fish that may nip at fins: Species such as Chinese Algae Eaters and some species of Plecos may harass Diamond Tetras and nip at their fins.

When introducing new fish species to a tank with your Diamond Tetra school, it’s important to monitor their behavior and ensure that they are not aggressive towards each other. A well-planned and well-stocked community aquarium can provide a peaceful and dynamic environment for your Diamond Tetras.

Diamond Tetra Care

Now that we’ve learned about the origins and ideal tank mates for these fish, let’s delve into the essential aspects of Diamond Tetra care. Ensuring they feel right at home in your aquarium is paramount for these aquatic gems to thrive and display their full, sparkling beauty.

Tank Setup

A well-designed tank setup is crucial to the health and happiness of your Diamond Tetras. As someone who has set up multiple aquariums, I can attest to the importance of paying attention to the smallest details. Here’s what you need to consider:

Tank Size

Fish of this species are active swimmers and thrive in groups, so providing adequate space is essential. A 20-gallon tank is the minimum I would recommend for a small group of at least six Diamond Tetras. However, a larger tank would be even better, especially if you plan on keeping more fish or adding other compatible species.

When I first started keeping Diamond Tetras, I began with a 20-gallon tank, but soon upgraded to a 40-gallon one to give them more room to explore and school together.

What to Put in the Tank

These fish appreciate an environment that mimics their natural habitat. I’ve found that using a mix of fine sand and smooth gravel as a substrate, along with plenty of live plants, creates a comfortable and visually appealing environment.

Diamond Tetra swimmers love darting in and out of plants like Java Fern, Anubias, and Amazon Swords. Adding driftwood and rocks to create hiding spots and shaded areas is also highly beneficial.

Equipment and Accessories

Proper filtration is vital to keep the water clean and maintain a stable environment. I use a combination of mechanical and biological filtration to ensure optimal water quality.

Additionally, a heater is essential to maintain a consistent temperature, ideally between 75-82°F (24-28°C). To encourage natural behavior and enhance their iridescent colors, I recommend using a moderate to low lighting setup.

Water Parameters

Maintaining the right water parameters is crucial for the health and well-being of your Diamond Tetras. These freshwater fish are a relatively hardy species and can adapt to a range of water conditions, but it’s always best to keep their environment as stable as possible. Here are the key water parameters to keep in check:

  • Temperature: These fish thrive in water temperatures between 75-82°F (24-28°C). Using a heater with a thermostat will help maintain a consistent temperature in your aquarium.
  • pH Level: These fish prefer slightly acidic to neutral water, with a pH range of 6.0-7.5. Regularly testing the pH and making adjustments as needed will ensure that your Diamond Tetra thrives.
  • Water Hardness: Diamond Tetras can adapt to a variety of water hardness levels. However, they do best in soft to moderately hard water, with a general hardness (GH) between 5-19 dGH.
  • Ammonia (NH3): Ideally, ammonia levels should be as close to 0 ppm (parts per million) as possible. Even low levels of ammonia can be harmful to fish, causing stress and illness.
  • Nitrite (NO2): Like ammonia, nitrite levels should also be maintained at or near 0 ppm. Elevated nitrite levels can lead to stress, reduced oxygen uptake, and potential fatalities in fish.
  • Nitrate (NO3): While less toxic than ammonia and nitrite, high nitrate levels can still negatively impact fish health. Aim to keep nitrate levels below 20 ppm, although levels between 20-50 ppm are generally considered safe for most fish species. Regular water changes and good aquarium maintenance practices will help prevent nitrate buildup.

It’s essential to maintain high water quality in your aquarium. Perform regular water changes (I recommend 25-30% every two weeks) and monitor water parameters in your Diamond Tetra tank. You’ll create a stable and healthy environment where your fish can thrive and showcase their stunning colors.

Diet and Feeding

The aspect of Diamond Tetra Care that you’d take the most active part in is in feeding them. My own experience has shown me that it is critical to give them a variety of high-quality feeds to keep these fish happy and growing.

In their natural environment, Diamond Tetras generally eat tiny insects, crustaceans, and plants in the wild. To mimic this diet in your aquarium, feed them a mix of high-quality flake or micro-pellet dry food and live or frozen items like as brine shrimp, daphnia, or bloodworms on occasion. Personally, I’ve discovered that my Diamond Tetras like the thrill of chasing live meals, and it’s a joy to see them exhibit their innate hunting instincts.

Overfeeding your fish is dangerous since it can lead to poor water quality and health problems. Feed them tiny quantities one to two times each day, only as much as they can ingest in a few minutes. I’ve created a feeding schedule for my fish that keeps them busy and interested throughout the day.

Common Health Issues and Diseases

Even if they’re a hardy species, Diamond Tetras can be susceptible to health issues and common freshwater diseases if their environment is not properly maintained. Early detection and treatment can significantly improve the chances of recovery for your fish. Here are some common health problems that can affect this species:

  • Ich (White Spot Disease): Ich is a parasitic infection that manifests as small white spots on the fish’s body, fins, and gills. It’s often caused by poor water quality or sudden changes in temperature. If your Diamond Tetras show signs of Ich, increase the water temperature to 82-86°F (28-30°C) for a few days and treat the tank with a suitable Ich medication.
  • Fin Rot: Fin rot is a bacterial infection that causes the fins to become ragged and discolored. It’s usually a result of poor water quality or injury. To treat fin rot, ensure optimal water quality through regular water changes and use a recommended antibacterial medication.
  • Fungal Infections: Fungal infections can occur when water quality is compromised, and they appear as cotton-like growths on the fish’s body or fins. Treat fungal infections by improving water quality and using an antifungal medication specifically designed for aquarium use.

Prevention is always greater to cure. Maintaining a clean and stable environment, monitoring water conditions on a regular basis, and giving a balanced diet will reduce the possibility of health issues and create a thriving habitat for your Diamond Tetras. Always keep in mind that a good environment results in healthy, lively fish.

diamond tetra

Breeding Diamond Tetras

Care to try to breed Diamond Tetras? You’re in for a rewarding experience for any fish enthusiast. I’ve had the pleasure of breeding these beautiful peaceful fish myself and would like to share some insights and tips to help you through the process.

Gender Differences

Identifying the differences between male and female Diamond Tetras is essential for successful breeding. Males tend to be slightly larger and more colorful, with elongated dorsal fins. Females, on the other hand, are generally smaller, with rounder bodies and less vibrant colors.

The Breeding Process

The steps to breeding many types of tetras are generally the same, with a few specific tweaks. Here’s the gist of it:

  1. Set up a separate tank for breeding with soft, slightly acidic water and plenty of fine-leafed plants, such as Java Moss or spawning mops, to provide suitable surfaces for egg-laying.
  2. Maintain a slightly higher water temperature (around 80°F or 27°C) to stimulate spawning.
  3. Introduce a healthy, mature pair of Diamond Tetras into the breeding tank.
  4. Feed the fish high-quality live or frozen foods to condition them for spawning.
  5. Once the fish are ready, the female will scatter her eggs among the plants, and the male will fertilize them.

Breeding Tips

Here are some handy tips to remember for a higher chance of success at breeding Diamond Tetras:

  • After the eggs are laid, remove the adult fish from the breeding tank to prevent them from eating the eggs.
  • The eggs will usually hatch within 24-36 hours, and the fry will become free-swimming after about 3-5 days.
  • Provide the fry with suitable food, such as infusoria or commercially available liquid fry food. As they grow, gradually introduce baby brine shrimp and finely crushed flake food.
  • Perform regular water changes and maintain good tank hygiene to ensure the healthy growth of the Diamond Tetra fry.

Related Species

The Diamond Tetra is part of the Characin family (it’s also called Diamond Characin after all), which all tetras are classified under. If you’re a fan of its shimmering beauty, check out these other metallic and jewel-like tetras:

  • Cardinal Tetra (Paracheirodon axelrodi): Similar in appearance to Neon Tetras, Cardinal Tetras have a more extended red stripe that covers almost the entire lower half of their body. The combination of blue and red creates a striking visual effect in the aquarium.
  • Rummy Nose Tetra (Hemigrammus rhodostomus): Rummy Nose Tetras are distinguished by their red noses and unique tail patterns. They have a silvery body with a metallic sheen that glistens under the right lighting conditions.
  • Emperor Tetra (Nematobrycon palmeri): Boasting a regal appearance, Emperor Tetras have an iridescent blue-green body with black horizontal stripes and yellow or orange accents on their fins. They add a touch of elegance to any aquarium setup.
  • Green Neon Tetra (Paracheirodon simulans): These small tetras may appear similar to their neon counterparts, but they exhibit a subtle green iridescence that sets them apart. Their delicate beauty makes them a favorite among many hobbyists.


Are Diamond Tetras fin nippers?

While some tetra species may exhibit fin-nipping behavior, Diamond Tetras are generally peaceful and not known to be aggressive fin nippers. However, individual fish may display varying behaviors, and it’s essential to observe your fish and address any aggression promptly.

How can I enhance the color of my Diamond Tetras?

Offering a varied and high-quality diet, maintaining optimal water parameters, and providing a stress-free environment will contribute to the vibrant colors of your Diamond Tetras. Using dark-colored substrates and a well-planted tank can also help accentuate their colors.

Can Diamond Tetras be kept with shrimp?

Diamond Tetras can coexist with shrimp in a community tank, but there’s a possibility that they might prey on smaller shrimp or their fry. It’s recommended to provide plenty of hiding spaces for the shrimp to minimize potential predation.

How can I tell if my Diamond Tetra is stressed?

Signs of stress in Diamond Tetras may include a loss of color, erratic swimming, hiding or staying near the surface, and a lack of appetite. Investigate potential stressors, such as poor water quality, incompatible tank mates, or illness, to address the issue and restore your fish’s health.

How fast do Diamond Tetras grow?

The growth rate of Diamond Tetras can vary depending on factors such as diet, water quality, and tank conditions. Generally, they can reach the average Diamond Tetra size of 2-2.5 inches (5-6.5 cm) within 9-12 months.

Are Diamond Tetras Right for Your Aquarium?

Deciding whether Diamond Tetras are the perfect addition to your aquarium comes down to your personal preferences and commitment to providing the best possible environment for these captivating fish. With their iridescent colors, peaceful temperament, and manageable care requirements, Diamond Tetras can be an excellent choice for both beginners and experienced aquarists.

By following the guidance provided in this blog post and dedicating yourself to understanding and meeting their needs, you’ll be well-equipped to create a comfortable and healthy habitat for your Diamond Tetras. In return, you’ll enjoy the shimmering beauty and mesmerizing charm they bring to your aquarium.

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