Diamond Tetra 101: Complete Care Guide (2024)

Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: April 9, 2024
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The Diamond Tetra, recognized for its green sparkle that dances around its sleek, silver body, is an obvious selection for researchers. This aesthetically pleasing fish, which prefers warmer waters, is easy to keep and perfectly fits a range of aquarium settings due to its generally mild nature.

Article Summary

  • Diamond Tetras have beautiful, vibrant colors that fade with age, stress, temperature, or water issues, and males have longer dorsal fins than females, but their average lifespan is only 3-6 years.
  • For Diamond Tetras, it is recommended to have a tank resembling their natural habitat with warm, clean water, plenty of plants, and a minimum size of 15 gallons for 2-3 tetras (larger for more).
  • Diamond Tetras require a balanced diet that includes a variety of foods, such as live or frozen brine shrimp, red blood worms, and leafy greens, and should be fed multiple times a day while removing any uneaten food within 30 minutes.

Whether you’re just getting started with a diamond tetra or simply looking for more information about these beautiful animals, read on to see just what is to love about the Moenkhausia pittieri.

The diamond tetra is a member of the Characoid family, originating in Africa and South America.

Characins are notable for their common possession of teeth on either bottom or top of the mouth, and or an adipose fin which is located between the dorsal and tail fin towards the back of the fish. In this instance, diamond tetras have both teeth and an adipose fin.

Diamond Tetra (Moenkhausia pittieri)
(1) Diamond Tetra (Moenkhausia pittieri)


Diamond tetras aren’t normally an aggressive fish in their natural environment, but in some instances may still nip as many toothed fish do. This happens seldomly, and will rarely if ever progress into actual fighting.

These fish share several common characteristics with the carp family (Cyprinidaeand may be easily mistaken for them at first, but as one learns what to look for it becomes much easier to differentiate.

Carp possess neither adipose fins nor teeth in the jaws, making them tricky to distinguish, but not impossible.

Relatively angular in shape, with long and pointed fins and a laterally compressed body, the diamond tetra shares its stout shape with many other Characoids.

These freshwater fish are incredibly hardy and can be quite long lived for a fish of its size. The average diamond tetra lifespan is around 3-6 years in most well maintained tanks.

What Color Are Diamond Tetra?

Diamond tetra can be described as pearly in coloration, with a silver body interspersed with pigments of green to gold. As they swim, these colors flash in the sunlight, creating a lovely glittering movement.

The diamond tetra’s underside is a shade of blue, which stands out vividly against the bright red color of their eyes. This red is especially visible on the upper half of the eye, with the bottom being a more golden color.


Young diamond tetras start out relatively dull in color, and will gradually come into their full splendor at around 9 months old.


Diamond tetras are a small freshwater fish, growing to a maximum of around 2.4 inches in length. Juveniles fry start as eggs around 0.3 inches in size, and will quickly grow to their full size after a period of 5-6 months.

Unique Features

The diamond tetra is uniquely notable for its prominent, pointed dorsal fin and dazzling display of colors. Unlike certain other species of Characin, they possess both teeth in their jaws and a small, round adipose fin on their back.

Males and Females

Diamond Tetra with long fins
(2) Diamond Tetra

After reaching adulthood after 9 months, diamond tetra fry will begin to show sexual differentiation. Males generally have longer dorsal fins, with those of females being shorter and less sharply defined.

Can diamond tetras lose color?

As with most other fish species, the vivid colors of the diamond tetra are by no means static. As your fish ages, its color will naturally begin to fade as the color producing pigments lose their capacity to continue functioning.

Additionally, fish who are suffering from stress, shock from temperature or water conditions shifting, issues with diet, or bacterial infection may show a loss of color.

Returning conditions in your tank to their normal state will do wonders at getting your fish back to their original color.


If you suspect that your fish is ill, I recommend isolating them in a separate quarantine tank until you can seek a proper veterinarian and determine a course of treatment.

Are Diamond Tetras Aggressive?

Diamond tetras make good neighbors for a variety of fish. That being said, those who tend to be more aggressive or territorial should never be in the same tank as Diamond tetras. These fish will not initiate fights and are not outwardly aggressive, but will defend themselves if provoked.


If you’re already caring for a known aggressor such a betta or tiger oscars, I recommend considering the use of a separate tank. It may be a bit more of a hassle to maintain two, but separate tanks will ensure that neither fish is injured or killed in an altercation.

What fish can live with Diamond Tetras?

Diamond tetras are schooling fish in their natural habitat and do well in groups of up to 5 at a time. These are good community fish, and will only rarely come into conflict with one another.

In addition to other diamond tetras, fish with similar dispositions and habits such as danios, rasboras, and other tetra varieties such as emperor tetra and silvertip tetra make for a good match.

Suitable tank mates for diamond Tetras

When it comes to the best tank mates, diamond tetras get along well with other livebearers, medium-sized cichlids, and peaceful bottom dwellers like plecos or freshwater catfish can be an excellent fit.

Additionally, invertebrates such as aquarium snails and shrimp will see no trouble from these amicable tank mates.

Tank Size

A minimum tank size of 15 gallons is a good place to start for a smaller group of 2-3 diamond tetras. Beyond this, you’ll want to consider looking at a larger tank so that they do not become crowded and vie for space with other species.

20 Gallon Fish Tank
20 Gallon Fish Tank

A good rule of thumb here is 1 inch of fish per gallon of water in your tank. So for an additional two tetras beyond the first three, look at an additional 5 gallons, (2½” per fish x 2 fish = 5 gallons) of tank space.


When it comes to proper tank size, bigger is generally always better provided you can maintain adequate tank water parameters. If you’re having trouble keeping conditions in your tank stable and clean with a smaller tank, it may be time to consider upsizing.

Water Temperature

These tropical fish prefer things on the warmer side when it comes to water temperature. The diamond tetra thrives at a temperature of between 70 and 82 degrees Fahrenheit.

As a hardy species they are somewhat adaptable to shifts, but seeing a rapid temperature rise or fall will likely lead to a sick fish suffering from the effects of temperature shock.


Lake fish like the diamond tetra enjoy a dark, calm environment. Providing reduced light level, darker substrate, and floating plants above will allow your tetras to feel safe and secure, along with providing foreground plants for them to hide in and break line of sight.

Creating a consistent day and night cycle for your fish can help them reduce stress and create a sense of stability in your tank. Allow for a period of 8-12 hours each day with a completely dark tank to give your fish ample time to.


Alternatively, providing constant, overly bright lights can rapidly stress your fish. A fish suffering from the effects of stress is much more susceptible to the effects of common freshwater diseases such as dropsy and fin rot, meaning some simple planning can do much for their long term health.

Consider adding a timer to your tank accessory arsenal to make keeping a consistent cycle easier on you, the aquarist.


As with most fish, diamond tetras require a fully adequate and functional filtration system in order to thrive. Even sparsely decorated environments free of leaf litter will need filtration to prevent the occurrence of parasitic infections and bacterial diseases.

Additionally, be sure to consistently be changing your water. A rate of 10-15% total water volume change per week, or 20-25% every two should be adequate to keep things in good shape.

pH Level

The diamond tetra prefers a pH more in the slightly acidic direction between 5.5 and 7.5. A neutral tank (anything around 7pH) will suit them just fine, however, meaning that they can get along well with a variety of freshwater aquarium fish.

Water Hardness

A water hardness level of between 2 and 15 dGH should suffice for these and other tetras, which refers to the concentration of metal ions such as calcium and magnesium per gallon of water.


Planted Aquarium
Planted Aquarium

A general amazonian biotope setup is the general idea of what you want to aim for, with warm water, plenty of plants, and some good decorations to help bring everything together.

Having a few driftwood branches that have been well sanitized will be a great addition for your diamond and other tetras…

Having a few driftwood branches that have been well sanitized will be a great addition for your diamond and other tetras to hide in and feel right at home compared to the slow moving tributaries of their natural environment.


Diamond tetras live with plenty of plant matter in the lakes and streams of their natural habitat.

When designing the most comfortable space for these freshwater fish, aquarium plants such as java ferns and nubias will help give them space to hide, create natural shading inside your tank, and can even provide a snack in a pinch.


That being said, keeping your diamond characin well fed should keep it from munching on your java moss and other plant matter too often.

What Do Diamond Tetra Eat?

These freshwater fish are omnivores, meaning that when it comes to diet diamond tetras need a good balance of animal protein and vegetation to remain healthy.

Keeping this fish well fed is essential to prevent it from eating aquarium plants, preferably with a leafy or vegetable diet supplement.

Feeding them fresh or frozen brine shrimp, red blood worms, and mosquito larvae, supplemented with leafy greens like lettuce is a great way to ensure that you meet their dietary needs.

Fish flake food
Fish flake food

Additionally, a high quality flake food is a great choice for your fish food. Make sure to choose one that has been specifically formulated for fish like tetras, as other fish may have different requirements than your Moenkhausia pittieri.

How Often To Feed Diamond Tetra

Multiple feedings of around 3 times a day should suffice for these hungry fish. The trick is to make sure that you aren’t overfeeding with foods like pellets or baby brine shrimp, so only provide as much food as they can eat within a 3 minute period.


A good rule of thumb for preventing feeding from interfering with your water quality is to remove any uneaten food within a half an hour of feeding. This will ensure that leftover food doesn’t have time to break down, meaning your fish can remain healthy and happy without swimming through dirty water.

Providing a live, free swimming option like live brine shrimp or worms can help to engage the natural predator instinct of your diamond tetra. They’ll chase their fish food around a bit before eating, allowing them to expend energy and generally be more active while they eat.

Live foods can be somewhat more expensive and harder to keep, but should be easily available from most pet stores.

Can you breed diamond tetras?

You can absolutely breed diamond tetras (and many other tetra species like the lemon tetra) easily at home! All that it takes is a little preparation, some good care, and patience and you can have your own spawning set up in no time.

How To Breed Diamond Tetras

Diamond Tetras in Aquarium
(3) Diamond Tetras in Aquarium

To start with, decide if you’d like to focus more on a single breeding pair or rather a small group of up to 6 pairs of male and female diamond tetras.

Pairing success is largely determined by similarities in size and age, so don’t be surprised if it doesn’t occur on the first go around.

Separate Tanks

Next, you’ll want to prepare a separate breeding tank for the diamond tetra fry, along with one for each of the sexes of your fish.

The fry tank should have plenty of java moss and spawning mops along the bottom, to provide room for these egg layers to deposit their newly fertilized eggs.

Temperature and Lighting

In order to induce spawning, you’ll want a dim tank and a temperature of between 79 and 84 degrees Fahrenheit. This warmer temperature will speed up the metabolism of your tetras, and ensure that the eggs have a comfortable environment in which to develop.

Food for Breeding

Feed your tetras plenty of nutritious food and live options to get them in good condition during the breeding season. After a day or so of good feeding, add your pairs together in the breeding tank.

From Eggs to Fry

After one to two days after fertilization, the eggs should hatch. The tiny fry will grow quickly and need exceptional fry food, such as microworms or baby brine shrimp.

After a few weeks they should be a large enough size to consider adding into your main tank, and will develop their classic iridescent scales after around 9 months.

For additional information and tips about breeding diamond tetras, watch this video below.



Throughout today’s article, we’ve looked at the many facets of the diamond characin. We’ve looked at how to set up a tank with regards to tank mate, conditions, and even breeding, along with providing a well balanced diet for your fish.

Diamond tetras can be a rewarding fish without much challenge to take care of, once your tank care routine is well established.

Feel Free To Share

As always I hope that you’ve enjoyed today’s post and that it has answered all of your diamond tetra care questions.

Feel free to share this information with any other fish fanatics you may know, and I wish you the best of luck on your continued aquarium adventures!

(1) “Diamond Tetra” by kevitra is marked with CC BY-NC-ND 2.0
(2) “Newport Aquarium 06-15-2018 30 – Diamond Tetra” by David441491 is marked with CC BY-NC-ND 2.0
(3) “Newport Aquarium 06-15-2018 29 – Diamond Tetra” by David441491 is marked with CC BY-NC-ND 2.0

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