Diamond Tetra: Species Profile

Category: Tetra

Common Names: Diamond Tetra

Scientific Name: Moenkhausia pittieri

Family: Characidae

Minimum Tank Size: 10 Gallons

Care Level: Moderate

Temperament: Peaceful

Max Size: 2 Inches

Temperature: 76-82 F

pH: 6.0-7.5

Tank Level: Bottom to Middle

Colors: Silver, Orange

Diet: Omnivore

Breeding: Moderate

Diamond Tetra from the Left Side

Diamond Tetra: Species Overview

Diamond tetras have an unassuming appearance compared to other tetra varieties, but that hasn’t stopped them from becoming popular aquarium fish. Indeed, these tetras have attractive fins and a calm nature, making them a favorite in freshwater tanks.

Beginners can feel comfortable knowing that diamond tetras are easy to care for. They also get along well with other fish, so you don’t have to worry about breaking up any fights.

However, novice fish keepers still need to ensure that specific tank parameters are followed to ensure their diamond tetras stay healthy.

Distinguishing Features

If you’re familiar with other tetras, you might not initially expect the diamond to belong to the same family. That’s because these fish have wider and overall larger bodies.

You’ll be glad they have this extra surface area, given that they have seemingly solid silver-colored bodies. As they swim under a tank light, an iridescent shimmer emerges in several beautiful colors, including:

  • Blue
  • Green
  • Gold
  • Orange

Unlike some fish, which lose their coloring as they age, diamond tetras gain even more iridescence as they get older. A true diamond in the rough!

In addition, diamond tetras have a small red splash of color on their upper eyelid.

Aside from that unique feature, diamond tetras have transparent fins, although they usually have a hint of a violet tone.

The violet tone is especially noticeable on the anal fin, which is longer than the other fins.

Neale Monks [CC-BY-SA-3.0]


Diamond tetras inhabit a relatively small area in Venezuela. They’re native to Lake Valencia and the tributaries that surround it.

These fish thrive in areas with lots of living plant vegetation and decaying organic matter. As a result, they won’t be adversely affected by murky freshwater, but it’s best to ensure your tank’s water is of high quality.

Although diamond tetras don’t regularly visit the bottom of where they live in the wild, they populate shallower areas with a substrate containing many decaying plants mixed with sand and stone.

These fish enjoy the warm water where they’re from and prefer habitats with a neutral pH.


Diamond tetras grow between 2 to 2.5 inches long.

There’s little difference in length between males and females. But when a female is preparing to lay eggs, she’ll have a stockier appearance.


Diamond tetras have a wide range in their lifespan—three to six years.

How long your diamond tetras will live will depend on several factors, including:

  • Genes
  • Food quality
  • Correct tank parameters
  • Introduction of healthy fish in the tank

As a fish keeper, you have control over all situations except the genes. So, by following the advice we’re sharing here, you can give your diamond tetras the best chance at reaching the longer end of their potential lifespan spectrum.


Unlike many types of tetra, it’s easy to tell the difference between the male and female diamond variety.

Females have a short dorsal fin with a slightly more rounded appearance. In contrast, males have longer and pointier dorsal fins.


Diamond tetras are mostly peaceful, even-tempered fish.

They thrive in community environments and need other diamond tetras to school and socialize with. A strange phenomenon with this species is that they like to school in odd numbers.

With that in mind, we recommend owning a minimum of three diamond tetras. But the more pairs you can add in addition to that, the better.

You can feel comfortable placing several other fish species in a diamond tetra tank. Since these fish enjoy hanging out with each other, it’s rare to see them antagonize their tank mates.

However, you might occasionally witness diamond tetras acting aggressively with each other. These spurts are usually short, and these bouts are not influenced by factors like gender.

Diamond Tetra Zoomed Out

Tank Parameters

If you’re ready to welcome diamond tetras into your family, it’s time to set up their tank. The information below will ensure your fish have the best chance of having healthy and happy lives.

Minimum Tank Size

Diamond tetras require a minimum of five gallons per fish. Since you should place at least three of these tetras together, you’ll need to start with a tank size of 15 gallons.

That said, the more space you can offer your tetras, the happier they’ll be.

At the least, you should aim to purchase a tank with 24” x 15” x 12” dimensions.

Water Parameters

Diamond tetras are relatively hardy for tropical fish, but it’s still vital to ensure their tank water remains within the following parameters.


Diamond tetras enjoy warm water between 72°F to 82°F.

Ideally, you should aim for the mid to upper 70s so that it’s in the middle of this range. Since most homes dip below 72°F at certain times, using a tank heater is vital for maintaining a consistent temperature for your tetras.


The ideal pH for diamond tetras is 6.0 to 7.5, which is a slightly narrower range than certain other tetra species.

According to your water’s baseline, you can use store-bought chemicals to alter the pH to higher or lower. Diamond tetras prefer a pH just below neutral (7.0), so aim for a pH in the upper six’s.


You should never place diamond tetras in a saltwater tank. These are freshwater fish, so high salt concentrations will kill them.

In some cases, you can add a small amount of salt to deal with parasites. However, it’s essential that you take care when doing so given the risks posed by salt.

Tank Setup

Getting the correct water parameters is essential, but it’s not the most fun part of fish keeping. So, let’s move on to the details about setting up your diamond tetra’s tank so that you and them can enjoy it.


The substrate you use isn’t make-or-break for diamond tetras, given that these fish primarily remain towards the middle and top of an aquarium.

But it’s always wise to reproduce their natural habitat as best you can. So, aim to use sand as a substrate.

When possible, dark sand is best, as that’s what these fish see in the wild. Another advantage of a dark substrate is that it makes your diamond tetra’s silver and iridescent colors stand out even more.


Decorations are an equal joy for you and your diamond tetras, given that these are curious, playful fish. The right kind of decor can also offer your tetras some hiding spaces, helping to keep their stress levels low.

Some excellent decorations include driftwood, sunken logs, and rocks.

Try to build caves out of the rocks that are high enough to reach into the middle or upper portion of the tank. Similarly, using branches or logs that jut into these areas is equally important, as this is where diamond tetras spend most of their time.

That said, don’t overdo it with decorations. After all, your fish will want open space to swim and school.


Adding plants to your aquarium is even more critical than decorations, given that diamond tetras live in densely planted areas in the wild.

Not only do plants provide these fish with food and shelter, but they also block out direct sunlight, something that diamond tetras strive to avoid.

You can get creative with mixing and matching the plants you use, but we recommend combining floating plants with those that grow from the ground up.

Some excellent options include:

  • Water lettuce
  • Red root floater
  • Hornwort
  • Java fern

It’s best to place these plants around your tank’s perimeter. Doing so will ensure your diamond tetras will still have room to swim.


Diamond tetras don’t need a lot of light. In fact, a dim light is fine if they’re the only fish in the tank.

Otherwise, if you have other species that require brighter light, it’s all the more important to have areas in the tank with thick plant vegetation.

That way, your diamond tetras can escape the brightness.


Diamond tetras won’t live long if you don’t set up a filter in their tank, given that bacteria and toxins will rapidly build up in the water.

So, choose a high-quality filter that’s well-suited to the size of your aquarium.

You’ll need to check the filter regularly to clean it, but relying on a filter alone for keeping the water clean is a recipe to make your fish sick. Indeed, routine 25% water changes every one to two weeks are necessary to keep the water in optimal condition.


Installing a heater is the best way to ensure your diamond tetras have access to a comfortable water temperature year-round. You’ll have plenty of heaters to consider, with several energy-efficient models on the market.

One good investment would be a thermometer to keep in the tank. With this handy device, you’ll catch any temperature changes should the heater malfunction.


In the wild, diamond tetras live off plants, insects, and other small crustaceans they encounter.

That means these omnivores are versatile with their food choices, so it’s unlikely they’ll stick their noses up to whatever you offer them.

Using fish flakes or pellets is an excellent start for ensuring your diamond tetras have the proper balance of nutrients. But it’s also helpful to add other options such as:

  • Brine shrimp
  • Bloodworms
  • Daphnia

You can feed your fish the live, dried, or frozen versions of these protein-based foods.

A diamond tetra should ideally be fed two or three times daily. After they feast on their food for two or three minutes, remove whatever remains so that they don’t overeat.


Breeding diamond tetras isn’t the easiest task. But if you have patience and know the background of the species, it can be worth a try.

The reason for the challenge is that diamond tetras will only spawn with fish around their same age and size. To create the right conditions for breeding, it’s best to move these fish to a separate breeding tank with the following conditions:

  • Minimum of 20 gallons
  • Slightly acidic water
  • Low water hardiness

You’ll also need to include plants or spawning moss to catch the eggs.

Keeping a tank light set at low and then gradually increasing its strength will encourage your diamond tetras to spawn.

Move the adult fish out of the tank once they finish spawning to prevent them from eating the eggs. You can expect the eggs to hatch in one to three days.

Then, feed your infant diamond tetras baby brine shrimp until they’re big enough to join the others.

Common Diseases

Here’s the good news: Diamond tetras don’t have a high rate of contracting diseases.

But no fish species is immune to disease. Furthermore, fish keepers can inadvertently cause illnesses by adding infected fish to a tank or not maintaining the proper water parameters.

Some of the most common diseases that diamond tetras fall ill with include:

  • Ich
  • Fin rot
  • Velvet disease
  • Fungal infections
  • Bacterial infections

Ich and velvet diseases are parasitic infections originating from the Ichthyophthirius multifiliis and Piscinoodinium pillulare parasites.

Diamond tetras contract these parasites from other infected fish. For this reason, it’s vital to quarantine new fish before adding them to your tetra’s tank.

That way, you can observe them for signs of illness.

Fin rot, fungal infections, and bacterial infections are often the result of poor water conditions.

Sometimes, the water parameters are at fault. Other times, the issue is that the fish keeper hasn’t changed the filter or water recently, causing toxins to build up.

Regardless of the reason, you’ll need to perform a 50% water change to remove a significant amount of the toxins. Applying antibacterial or antifungal medication is also often necessary.

No matter what disease your diamond tetra has, acting fast is crucial to reducing the chance of death.

Potential Tank Mates

Many options exist for pairing diamond tetras with other species. However, it’s important to pair them with peaceful fish that aren’t too big.

Some of the ideal tank mats for diamond tetras include:

  • Mollies
  • Guppies
  • Cory catfish
  • Other tetras

Keep in mind that snails and small shrimp make bad tank mates because they are at risk of being turned into a meal.