Neon rainbowfish Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: November 23, 2022

The neon rainbowfish is a beautiful and popular freshwater fish that is perfect for beginners. They are easy to care for and very tolerant of different water conditions.

This guide will teach you everything you need to know about neon rainbowfish care. You’ll learn about their diet, size, lifespan, and more!

Species overview

Neon rainbowfish (Melanotaenia praecox) are found across a wide area of northern Australia.

They inhabit a variety of freshwater habitats including rivers, creeks, and lagoons. However, they seem to prefer areas with a high density of plants and aquatic vegetation.

In the wild, neon rainbowfish are omnivores and will eat a variety of plant matter as well as small invertebrates.

Neon rainbowfish are a popular choice for freshwater aquariums due to their bright coloration. They are also relatively easy to care for, which makes them a good choice for beginner aquarium hobbyists.


Neon rainbowfish

The Neon Rainbowfish is one of the more popular freshwater fish due to its unique coloration. As you can probably guess from their name, these fish have a very neon appearance.

This is most notable on the males of the species who have a bright blue body with a neon green dorsal fin. The females are a bit more drab in comparison with a gray body and clear fins.

Both sexes have a dark stripe that runs from their snout all the way to the base of their tail. This stripe is much more visible on the males.

The Neon Rainbowfish is a small fish that only grows to be about 2 inches in length. They have a very thin and elongated body shape.

Their fins are all rather small and include a dorsal fin, anal fin, and caudal fin. The dorsal and anal fins are both rounded while the caudal fin is forked.


The average lifespan of a neon rainbowfish is 3 to 5 years. However, with proper care, they can live up to 8 years.


The maximum size of a Neon Rainbowfish is about 2 inches in length when fully grown. It’s not uncommon for these fish to stop growing at 1 inch depending on their level of care and genetic factors.


Tank Size

The recommended tank size for neon rainbowfish is a minimum of 20 gallons. If you want to keep a school of six or more fish, we recommend a 40-gallon tank or larger.

As with most fish, the more space you can provide the better. Neon rainbowfish are active swimmers and will often cruise the entire length of the tank in search of food.

Water Parameters

Neon rainbowfish are one of the few freshwater fish that can tolerate a wide range of water parameters. This makes them a great choice for beginners.

While they can live in a variety of water conditions, there are still some parameters you should aim for to ensure a healthy environment.

  • Water temperature: 72 to 82 degrees Fahrenheit
  • pH levels: 6.8 to 7.6
  • Water hardness: 2 to 15 dGH
  • Alkalinity Levels: 4-8 dKH

What To Put In Their Tank

Neon rainbowfish are one of the most popular freshwater fish for home aquariums. They’re relatively easy to care for and their bright colors make them a real standout in any tank.

When it comes to setting up their habitats, there are a few things you need to take into account.

First and foremost, these fish love to swim. A lot. They’re constantly on the move and prefer tanks that give them plenty of room to do so.

This means you should avoid anything that takes up a lot of space in the water column. Anything that reaches the surface (like floating plants) will just get in their way.

The substrate is another important consideration. Neon rainbowfish prefer a finer substrate so they can root around in it. They’re not the best diggers, but a sandy bottom will be much appreciated.

As for decorations, these fish are relatively un picky. Driftwood, rocks, and caves are all suitable. Just make sure whatever you use can’t easily be knocked over since they’ll be swimming around a lot.

Plants are a little trickier. They’re not impossible to keep with neon rainbowfish, but you need to be careful about the species you choose. Anything that doesn’t have a strong root system is likely to get uprooted (and eaten).

We recommend something like hornwort or water wisteria. These plants are tough and can handle a little abuse.

Common Diseases

Neon rainbowfish are actually quite resilient fish. They don’t seem to be very susceptible to the common diseases that plague other freshwater fish.

However, that’s not to say that they never get sick. Ich is the most common disease that affects this species, but other parasites and infections can occur too.

The best way to prevent your neon rainbowfish from getting sick is by keeping the water quality in their tank high. A clean and stable habitat will always lead to healthier fish.

Another thing you can do is to quarantine new fish before adding them to your tank. This will help to ensure that any potential diseases are not introduced to your existing fish population.

Behavior & Temperament

The neon rainbowfish is a beautiful, yet peaceful fish. It’s a mid-level swimmer that prefers to stay in the middle of the tank, but it will also swim near the surface from time to time.

This fish is relatively active and is known to be a good jumper, so make sure your tank has a tight-fitting lid!

Neon rainbowfish are schooling fish, so they do best when they’re kept in groups. They’re social creatures that need the company of others to feel comfortable.

When it comes to temperament, neon rainbowfish are peaceful, but they can be a bit nippy. They’re not aggressive, but they may nip at the fins of other fish. This is especially true if they’re kept in a tank that’s too small.

If you’re looking for a colorful, active fish that does well in a community tank, the neon rainbowfish is a great option!

Tank Mates

The neon rainbowfish is a peaceful community fish that does well with a wide variety of tank mates.

Because they’re so small, it’s important to choose fish that won’t view them as a meal.

Peaceful fish that occupy different parts of the water column are best. This way, everyone has their own space and there’s less of a chance for conflict.

Some compatible tank mates for neon rainbowfish include:

  • Guppies
  • Platies
  • Mollies
  • Swordtails
  • Tetras
  • Corydoras Catfish
  • Otocinclus Catfish


Neon rainbowfish are easy to breed in captivity. They’re not too picky about their water conditions and will readily spawn in a well-maintained aquarium.

To start, you’ll need to set up a spawning tank. It should be at least 20 gallons in size and well-filtered. You can use a sponge filter to avoid sucking up the fry.

Then, add some plants and other decorations for the fish to hide in. Neon rainbowfish like to have plenty of places to hide.

When ready, add two females for every male. Males are usually smaller and have more colorful fins.

Feed the fish plenty of live foods and high-quality flakes. Then, begin changing about 50 percent of the water each week.

This will help to trigger spawning.

You’ll know you’re successful when you see the female deposit her eggs on the plants. After she does that, the male will guard them.

When the eggs hatch, you can move the fry to a nursery tank. Feed them baby brine shrimp and other small live foods.

As they grow, you can start to feed them flakes. When they’re big enough, you can move them back to the main tank.


Neon rainbowfish are a great addition to any freshwater aquarium. They’re relatively easy to care for and add a splash of color to your tank.

They’re also a peaceful fish that gets along well with other community fish.

If you’re looking for a fish that is low-maintenance and beautiful, the Neon rainbowfish is a great option.