Diamond Tetras: Fascinating Care Tips and Tank Set-Up Advice

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Alison Page


Diamond Tetras

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The Diamond tetra makes a dazzling addition to any peaceful community tank, especially when you keep these stunning little fish in large groups.

These fish are relatively straightforward to care for, making them a good choice for beginner aquarists, and you can breed them pretty easily in the aquarium.

Keep reading to learn everything you need to know to keep these beautiful fish healthy and thriving!

The Diamond Tetra – At a Glance

Diamond Tetra Info
Scientific NameMoenkhausia pittieri
Common Name (species)Diamond tetra, Diamond characin, Pittier’s tetra
OriginVenezuela, specifically Lake Valencia and its associated waterways
Care LevelEasy
Average Lifespan5 to 8 years
Minimum Tank SizeAt least 20 gallons
Temperature Range75o to 83o F
pH Range5.5 to 6.5
Water hardness4 dGH or lower
Filtration/Flow RateGentle flow
Water typeFreshwater
BreedingEasy, egg-layers

Origins and Natural Habitat

Diamond tetras belong to the same family as other popular tetra varieties, including Neon and Cardinal tetras. These fish are widely available from good fish stores and online breeders. Although most specimens sold in the trade are farmed, some are wild-caught.

These fish are only found in one area in Venezuela’s Lake Valencia and its connected waterways. Unfortunately, pollution has dramatically affected the species’ natural populations, and they are now quite hard to find.

Not surprisingly, Diamond tetras prefer habitats with plenty of leaf litter and other natural debris where they can hide.

Diamond Tetra Lifespan

A healthy Diamond tetra can live for around five to eight years or longer in a well-maintained tank and when fed a varied, high-quality diet. It’s thought that these fish can live for ten years or thereabouts in the wild.


Diamond tetras are small fish that live in large groups in the wild. Both sexes look quite similar, having silver bodies and purple fins. That said, the males’ dorsal fins tend to be a lot longer and fancier than those of the females, and the male fish are somewhat more colorful and brighter.

The fish have red marks above their eyes and a dark midline band around their body.

How Big Are Diamond Tetras?

Diamond tetras grow to an average size of around two inches long, making them the ideal size for an average home fish tank.

Diamond Tetra Care Guide

Diamond tetras are popular fish that are a good choice for a beginner aquarist and make a bright, colorful addition to any peaceful community tank.

Here’s a comprehensive guide on how to care for them!

Tank Size

Diamond tetras are small fish, but they’re very active and need plenty of swimming space where they can shoal with their tank mates. If you want to keep other species with the tetras to create a community, you’ll need to factor that in, too.

So, we recommend keeping your Diamond tetras in a tank of at least 20 gallons or larger if you have the space for a bigger one.

The best tank shape to go for is a rectangular one, as that gives your fish lots of room to swim and plenty of surface area for good gaseous exchange.

Water Parameters

The Diamond tetra is a tropical fish that does best in water chemistry, which closely replicates that of its wild habitat.

The water temperature in a Diamond tetra aquarium should be between 75°F and 83°F, with slightly acidic pH levels of 5.5 to 6.5 and a water hardness of 0 to 4 dGH.

I recommend testing the tank water weekly with a decent-quality aquarium testing kit. That way, you can make any necessary adjustments to the water quality before problems start to affect your fish.

Use an aquarium vacuum cleaner when you perform partial water changes to get rid of uneaten food, dead plant matter, and organic waste, and clean or replace the filter media at least once a month to keep the system running efficiently and the water clean and healthy for your fish.

Tank Decoration

In the Diamond tetra’s natural habitat, there are plenty of plants where shy fish and fry can take shelter, so set up your tank with lots of bushy vegetation and include a few floating plants to provide shade and diffuse the tank lighting.

Driftwood, pebbles, rocks, and twisted roots provide hiding places and create a beautiful, natural look that works very well with this fish species. A few caves also add ambiance and provide good fish hideouts.


Diamond tetras don’t need any kind of special tank lighting, so a standard fish tank light will do fine. That said, if you want to try breeding your Diamond tetras, you’ll need an adjustable lighting system you can dim.

Water Flow Rate

In their natural environment, Diamond tetras inhabit water bodies where the flow is relatively slow and gentle, so you should try to mimic that in your tank.

These fish don’t appreciate being buffeted around by a strong current, so you’ll need to take steps to deflect the flow from your filter outlet if you have a strong pump. Some pumps have an adjustable outlet valve, but if yours doesn’t have that feature, you’ll need to buffer the flow with plants or decorations.

Tank Mates

Since Diamond tetras are such a peaceful species, you have a wide range of potential tank mates to choose from when setting up your community tank.

Essentially, any small, peaceful fish is a good fit for these tetras. However, you must keep your Diamond tetras in large groups of at least six individuals. Some hobbyists report incidents of fin-nipping, but that seems to be within the group if one fish becomes dominant.

I’ve kept Diamond tetras in a community tank containing guppies, corydoras catfish, and dwarf gouramis in the past without incident. Snails and shrimp also make suitable tank mates.

Fish to avoid are large, fast, predatory species that might bully or even try to eat the smaller tetras.

What Do Diamond Tetras Eat?

In the wild environment, Diamond tetras are omnivores, eating both plant and animal matter that they find in their immediate habitat. However, the fish’s diet is predominantly made up of meat, especially crustaceans, insects, worms, and insect larvae.

In the home tank, these tetras will thrive on a basic diet of tropical fish flake and pellet foods, supplemented with frozen meaty proteins, including bloodworms, mosquito larvae, daphnia, and brine shrimp.

That’s handy in a community setup because that diet suits most tropical fish species. When choosing commercially produced fish food, look at the ingredients list and pick something that contains protein and fat sources from the species the tetras eat in the wild.

How Often Should I Feed Diamond Tetras?

Ideally, you should feed your diamond tetras once or twice a day, offering only what the fish will eat in a few minutes.

Health and Disease

Although these are fairly hardy fish, they can develop a few common health issues.

One of the most common tropical fish diseases is called Ich or White Spot disease. This health condition is caused by a tiny aquatic parasite that lives in most healthy fish tanks, causing no problems until the fish are stressed or in poor condition.

If you notice your fish rubbing or flicking against solid objects within the tank, that’s a sign of problems. Within a few days, a rash of white spots like salt grains appears on the infected fish’s skin, fins, and gill covers. You can treat Ich with an over-the-counter product from good fish stores.

Tetras are also commonly affected by a condition called endocardiosis, which is an inflammation of the inner heart lining and is usually caused by an underlying infection.

Other common signs of sickness to be aware of include the following:

  • Ulcers or red areas on the skin
  • Ripped, bloody fins
  • Labored breathing
  • Sitting on the substrate
  • Inactivity
  • Poor appetite

Suppose your Diamond tetras display any of these signs. In that case, I recommend setting up a quarantine tank, isolating affected fish, and treating them with appropriate medication from your local fish store or vet.

Breeding Diamond Tetras

Diamond Tetras

If you fancy raising Diamond tetras in your home tank, the good news is that this species is relatively easy to breed under normal aquarium conditions. In fact, you might come to feed your fish one morning and notice eggs and even tiny fry swimming in your tank with no outside assistance whatsoever!

However, there are a few things you can do to encourage your Diamond tetras to spawn and raise the fry successfully.


The first thing to do is bring your breeding pairs of Diamond tetras into spawning condition. To do that, feed the fish extra portions of high-quality protein food to encourage them to gain weight and increase in size.

Spawning Tank

In the meantime, set up a dedicated breeding tank. The tank should be clean and well-maintained, with plenty of dense planting. Some breeders prefer to leave the aquarium bare-bottomed with just a fine net suspended above it to allow the eggs to fall through where they will be safe from other fish, including the parents.

Introduce the prepared breeding pairs to the spawning tank and raise the water temperature slightly by a few degrees. That mimics the increasing water temperature during the seasonal changes in the wild environment that trigger spawning behavior in this fish species. You should also add floating plants to the tank and dim the lighting.

Diamond tetras are egg scatterers, meaning the female fish lay their eggs randomly throughout the habitat, usually on plants. The male chases the female around the tank to encourage her to deposit her eggs, fertilizing them once they are released.

During and following spawning, you must increase the light supply gradually to imitate the natural lighting in the fish’s wild environment.

Raising the Fry

Once the eggs have been laid and fertilized, you must remove the parents. Diamond tetras play no part in raising their offspring and will likely make a meal of the eggs and fry if they get a chance.

It takes around 36 hours for the fry to hatch. At this point, you can feed them rotifers and commercially produced fry food. When the baby tetras are large enough, you can gradually switch to offering them adult meaty foods and finely crushed fish food flakes.

Availability and Price

Diamond tetras are a popular choice among fishkeepers, so they are usually readily available from good fish stores and pet shops, and you can also buy them online.

Expect to pay a few dollars per fish, although you can often get a discount if you get a group of fish, which is the best way to buy them since they need to live in groups.


In this part of our guide, we answer some of the most frequently asked questions about Diamond tetras and their care.

Q: How Many Diamond Tetras Should Be Kept Together?

A: Ideally, you should keep at least six Diamond tetras together, perhaps in a community with other peaceful species. However, the fish look spectacular when kept in even larger shoals, creating a stunning visual display in a well-decorated aquarium.

In the wild environment, Diamond tetras live in large groups, so you should never keep just one or two of these fish in your tank. That could stress the fish, causing health problems and shortening their lifespan.

Q: Are Diamond Tetras Fin Nippers?

A: Some owners have reported incidents of fin-nipping, although that seems to be only when the fish are kept in relatively small numbers. In those cases, a dominant fish tends to bully the others, but in a large group, that tends not to happen.

So, ideally, you should keep as many of these gorgeous fish as you have the space for.

Q: Should I Feed My Diamond Tetras Live Food?

A: If you have a reliable supplier, you can feed your Diamond tetras on live food as part of their diet. However, live foods often come with an unwanted cargo of parasites and bacteria that could harm your fish, so I generally don’t use them.

If you want to feed your fish live food, the best thing is to run your own home brine shrimp hatchery. Although that’s extra work for you, at least you know the shrimp are healthy and disease-free, and growing your own is much cheaper than buying them commercially.

Final Thoughts

Diamond tetras are popular freshwater fish that can make a lovely display in a peaceful community tank with other tetra species and non-aggressive small fish.

These brightly colored, active little fish must be kept in large groups in a big tank. You can breed them in your home tank relatively easily, and they’re pretty straightforward to care for. Keep the tank in good order by carrying out regular water changes, removing organic waste from the substrate, and maintaining your filter system properly, and the fish should thrive.

If you have Diamond tetras, tell us about your experience in the comment box below!

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