Black Neon Tetras – The Ultimate Care Guide

Black neon tetras (Hyphessobrycon herbertaxelrodi) are also known as black tetras, neon tetras, and black neons. They are members of the Characidae family and are peaceful schooling fish that are relatively easy to care for. This makes them a popular choice for both amateur and experienced aquarists. Successfully bred in captivity, they are also easy to obtain.

Hyphessobrycon herbertaxelrodi, the black neon, the aquarium pack.

Black Neon Tetras: Origin

Black neons are native to the Paraguay and Taquari River basins of southern Brazil where they inhabit tributaries, creeks, flooded forests, and sandbanks. Their natural habitat is very acidic, and the water is stained a “tea-brown” from an excess of tannins released from the breakdown of leaf litter along the bottom substrate.

Black Neon Tetras: Description

Unrelated to the “true” neon tetra (Paracheirodon innesi), they have a similar body shape and striking appearance. In contrast to the neon tetra with its blue and orange coloration, black neons have two distinct black and white lateral stripes that extend from the caudal fin to the gill cover on a silver body.  If you look closer, you can see shimmering green and yellow spots along the white stripe and below the black stripe.  There is some additional yellow coloration at the base of the caudal fin and a noticeable bright orange semi-circle above the large eyes.

Black neons grow to a little over 1-1.5 inches in length, but they are a schooling fish. This means you need to be prepared to take on at least half a dozen to keep them happy and plan your tank size accordingly.

The sexes are a little difficult to differentiate, but females have a slightly larger, more rounded belly than males, especially females that are carrying eggs.

Black neon tetra (Hyphessobrycon herbertaxelrodi) with a dark background.

Black Neon Tetras: Tank Set-Up

True to their native habitat, black neons prefer soft, acidic water, but they are adaptable and will tolerate hard, neutral water better than other tetra species. Though they’re small, they should still be kept in at least a 20-gallon tank (remember – they’re schooling fish). These fish are natural jumpers, so make sure you have a cover to prevent escapes!

An ideal tank set-up should include the following:

  • Subdued lighting
  • Live plants such as Amazon sword (a native plant found in their home region)
  • Open space for swimming
  • Dark substrate (river sand, driftwood, twisted roots, etc.) to help bring out the black neons’ natural coloring
  • Healthy water current in the middle of the tank (this is where they are most active)
  • Dried leaves – Indian almond is a great choice – to help replicate their natural environment and help dim the water; these will need to be changed every 2 weeks

As long as their water is kept clean, black neons are easy to care for. At least 25-50% of their water needs to be replaced every other week (water amount depends on how stocked your tank is). A proper filtration system will keep your tank and fish healthy, and a water change system will remove ammonia, nitrates, and other wastes while maintaining a proper balance of salts and minerals.

Basic water conditions should fall within these levels:

  • Temperature: 73-81F (23-27C)
  • pH: 5.5-7.5
  • Hardness: up to 6 dGH

Black Neon Tetras: Diet

In the wild, black neons are omnivores, feeding on small invertebrates, plants, crustaceans, filamentous algae, and fallen fruits. In aquariums, black neons are not picky, and they’ll eat pretty much anything they’re offered. However, the best feeding regimen should be varied to provide them with optimum health and color. An ideal diet should include:

  • Flake and/or frozen food
  • Live and frozen bloodworms
  • Daphnia
  • Mosquito larva
  • Brine shrimp
  • Moina

Black neons should be fed several times a day, but only an amount they can consume within 3 minutes or less. It’s also important to remember that they feed at the top of the water column; they aren’t bottom scavengers.  So, if you don’t have any fish working at the bottom of the tank, make sure to remove any excess food leftover after feedings to keep the tank clean and your filter free of debris.

Black Neon Tetras: Tank Mates

Black neons are peaceful, and they do great in community aquariums. They get along well with other schooling fish their size – such as neon tetras and cardinal tetras (pictured above) – as well as most other small tetras.

As mentioned previously, they feed in the top part of the water column, so it’s a great idea to pair them with bottom-dwelling catfish – such as Corydoras or Otocinclus – to help with that food clean-up.

Other fish black neons get along well with include:

  • Rasboras
  • Danios
  • Gouramis
  • Pencil fish
  • Guppies
  • Peaceful dwarf cichlids
  • Adult dwarf shrimps (your black neons will eat anyone younger)
  • Certain frogs
  • Bettas (who knew? Turns out this pairing actually works!)

You want to avoid larger fish that might decide your black neons would make a nice snack. The best rule of thumb: if the fish’s mouth opens wide enough to swallow the neon, they can (and probably will) eat it!

Black Neon Tetras: Behavior

If you notice your black neons nipping at the fins of other fish, odds are they don’t have a large enough school of their own. Provide enough “friends” for them to swim with, and this behavior should disappear.

A dispersed school within the tank is a sign of happy fish; they only bunch into a tight knot during times of stress. You might see this when you change their water, but don’t worry – they should relax from that tight pack once the water settles out again.

Black Neon Tetras: Common Diseases

One of the most common diseases that can affect black neons is neon tetra disease. This nasty little infection is the result of the microsporidian, Pleistophora hyphessobryconis (a spore-producing parasite), and it can affect any fish, despite its name.

The parasite is transmitted through the ingestion of infected dead fish or infected live food. The parasite begins to “eat” through the fish from the inside out, beginning with the digestive system. Freshly hatched embryos burrow through the intestinal tract and form cysts in the muscle tissue.  This causes the muscle embedded with the cysts to break down and die, turning pale, and eventually losing all color. When the cysts enter the water, they break open and release spores, infecting the entire tank. In fish with infected kidneys, cysts can also end up expelled through their waste.

Neon tetra disease can move through a tank quickly if you don’t recognize the signs and act fast to remove the infected fish.

Signs of the disease tend to progress in this order:

  • Restlessness, such as not schooling with the others, particularly at night (imagine having something burrow through your intestines – ouch!)
  • Loss of coloration: usually in one part of the body, eventually progressing across the entire body
  • Formation of lumps (this is a result of cyst formation and growth)
  • Difficulty swimming (remember, muscles are dying)
  • Curvature of the spine (this is seen in advanced cases)
  • Secondary infections (i.e., fin rot or bloating)

There is no cure for neon tetra disease.

Most fish have to be euthanized (really sad, but true), and recognizing the disease quickly so affected fish can be removed from the tank is the only hope for saving your other fish. Luckily, the parasite cannot be transmitted to humans, so you can handle the fish without fear.

How to prevent this nastiness?


Always purchase your fish from a respected supplier, and make sure to examine the tanks before you bring any fish home. If you see sick, dying, or dead fish, hightail it out of there and go somewhere else. (Helpful hint: sick fish don’t swim with the school)

Before adding new additions to your tank, set them up in a quarantine tank for at least two weeks and observe them for any signs of illness. This will not only give you a chance to watch for disease, it’ll give them a chance to acclimate to their new environment.

Keep your tank clean, and make sure you source your foods from a reputable supplier. There’s always a risk of contamination with live food (parasites are everywhere…seriously – they’re everywhere), but if you’re bargain shopping on the internet, your risk is going to go up.

If you do encounter neon tetra disease, bear in mind that the spores can inhabit your tank for six months – even without a host! So, keep your fish quarantined at least that long before you return them to the tank.

In addition to neon tetra disease (because that wasn’t bad enough?), black neons are subject to skin flukes, other parasitic infections (protozoa, worms, etc.), Ichthyobodo necator infection (the dreaded Ich), and general bacterial infections. Luckily, black neons are hardy, and as long as you’re maintaining proper cleanliness standards, they should be okay.

Just remember: plants, substrate, and decorations can all harbor spores and bacteria, so make sure you properly clean and quarantine ANYTHING you plan to introduce into your tank!

Black Neon Tetras: Breeding

Black neons are egg-layers that will spawn in schools or pairs. If they’re happy in their current aquarium, they may spawn on their own, but it’s also likely the eggs/fry will be eaten, so if you’re looking to breed your black neons, you’ll want to set up a separate spawning tank.

A 10-gallon tank is a suitable size, with dim lighting as the eggs are light-sensitive. If your room is bright, you can cover the sides of the tank with cardboard to help cut some of that light down. The water should be kept warm: around 75F (24C) while your selected breeders are getting acclimated, then increased to 80F (26.7C) several days later. You also want to aim for soft (4 or less dGH), acidic (pH 5.5) water. Aquarium-safe peat makes a great filter and will help encourage spawning.

You want to make sure you provide a “spawning” medium in the form of fine-textured, live plants or a layer of fine mesh. If using mesh, make sure the grain is wide enough for eggs to pass through but small enough to keep the adults out, or all your efforts are going to come to naught. (The breeders are going to want to replenish their energy after spawning, and those eggs will be too great a temptation) An alternative to mesh or plants is a yarn mop (easier to clean, and it won’t break down in the water).

Neon Tetra Fish Facts, Eggs

Now that your spawning tank is ready to go, it’s time to select your breeders:

  • Youngsters will spawn, but you should go with mature fish (at least one year of age)
  • Select the most colorful males
  • Females will “fatten up” when they are ready to spawn
  • You’ll want one or two males and several females

To optimize your chances, condition your selected breeding group by feeding them live foods (brine shrimp and mosquito larva are a good idea).

Black neons spawn first thing in the morning. The females produce hundreds of eggs which will hatch within 22-26 hours. As soon as all of the eggs are laid, transfer the adults back to their tank (otherwise, your fry are going to turn into snacks). The fry will appear in about 3-4 days, and, lucky for you, they’re pretty easy to raise. For the first few days, they should be fed Infusoria-type foods. When they’re a little larger, they can be transferred to microworms or brine shrimp nauplii.

Juvenile black neons are gray with horizontal dark stripes.  At 3 weeks, they gain the shimmer of their parents, the black stripe, and their eyes start to change color. At 5 weeks, they resemble the adults, and they should be large enough to safely join the community tank.

Black Neon Tetras: Lifespan

In the wild, black neons tend to live an average of 8 years. Aquarium life predicts a life span of 5 years, but with a healthy environment, they can live up to 10 years. The best indicator is going to be water quality, a varied diet from a healthy source, and a proper schooling community. The more you do for your black neons, the longer they’re going to hang around to delight your eye.


Black neon tetras are peaceful, easily-cared for additions to many community aquariums. Striking in appearance, they make agreeable tank mates to other small schooling fish. They’re a hardy tetra, provided they’re kept in a healthy environment, and they thrive on a variety of foods and tolerate a wide range of water conditions. They are relatively easy to breed in captivity, making them a fun hobby for aquarists and easy to obtain for both the amateur and professional. With their black and white stripes, the black neon tetra makes a charming addition to any aquarium.

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