a close up of a rainbowfish swimming in their aquarium near an aquatic plant

Are you looking for a colorful, peaceful fish to add to your aquarium? If so, Rainbowfish may be the perfect choice for you!

Rainbowfish are a family of small, brightly colored fish that come. They are native to the streams, lakes and rivers of Australia, New Guinea, and parts of Indonesia. They are popular among aquarium owners because they are peaceful and easy to care for. They also have beautiful colors that can brighten up any tank.

Rainbowfish come in a variety of colors and patterns, from bright reds and blues to more subtle shades of yellow and orange. They can also have stripes, spots, or other markings. No matter what color you choose, Rainbowfish are sure to add beauty and life to your aquarium.

Rainbowfish are omnivorous, meaning they eat both plant and animal matter. Rainbowfish should be fed a variety of foods, such as flakes, pellets, frozen foods, and live foods. They are a very fast growing fish, and will mature within a year.

Rainbowfish are very active and energetic, and enjoy swimming around in their aquarium. They are very curious, and will enjoy investigating everything in their environment. They are known as very friendly and sociable fish. 

Rainbowfish are social creatures and do best when kept in groups of at least six. They can be kept with other peaceful fish, such as tetras and danios, but should not be kept with aggressive fish like cichlids. Rainbowfish also need plenty of swimming space, so it is important that they have a large enough tank.

Rainbowfish are one of the most popular freshwater fish for aquariums, mostly because they are so easy to care for. Most of them are very hardy, and so long as you keep the water clean and stable and feed them, they will stay healthy. 

Rainbowfish are very easy to care for, and will only require basic maintenance. Some Rainbowfish are relatively inexpensive, costing less than $10 per fish. Depending on the type you are interested in, others can be $15 to $30 per fish.

Rainbowfish are active fish that love to explore their environment. They will often swim around the tank looking for food and hiding places. They are also very social, so it is important to make sure they have plenty of space and hiding places so they can interact with each other.

Overall, Rainbowfish make great family pets that are easy to care for and add a lot of color and life to your aquarium. They are peaceful fish that get along well with other peaceful species, and their bright colors will add a splash of color to any tank. So if you are looking for a colorful, peaceful fish to add to your aquarium, Rainbowfish may be the perfect choice for you!

Rainbowfish Information

  • Average length: 4.5 – 6 inches
  • Attention Required: Low
  • Tolerance to Heat and Cold: Yes
  • Good Pet: Yes!
  • Good with Other Rainbowfish: Yes
  • Good with Other fish species: Yes
  • Suitable to live in an Apartment: Yes
  • Good for Less Experienced Pet Owners: Yes
  • Training: They have associative learning capabilities
  • Health Concerns: Fin rot and Ich disease
  • Allergies: None
  • Average Life Span: 5 – 10 years

There are so many Rainbowfish sub-species but only a few are good for keeping as pets. Some of the most common species are listed here.

  • Red Rainbowfish
  • Madagascar Rainbowfish
  • Neon Rainbowfish
  • Boeseman’s Rainbowfish
  • Lake Kutubu Rainbowfish
  • Desert Rainbowfish
  • Lake Wanam Rainbowfish

Physical Appearance of Rainbowfish

a close up of a silver and yellow colored rainbowfish

The fish have a long thin body and the males tend to have a hump on their backs. When the eggs hatch, the fry usually appear silverish. As the fish grow bigger, the vibrancy and variety of their colors start appearing. The Rainbowfish can take on any color depending on the species. The lower part of their bodies usually has a pink tinge while the rest of the body looks either silverfish, bluish, or greenish. Their fins are either red to orange, or clear.

Temperament of Rainbowfish

The Rainbowfish are peaceful and enjoy living in schools of about 6. They do well with other fish species in their tank as long as they are peaceful. Rainbowfish rarely bite other fish but it’s not uncommon for them to chase other fish in their tank. Rainbowfish are very active and prefer swimming from the middle or the surface of their aquarium.

It’s also worth noting that when stressed, they will often hide among substrates and plants in the aquarium.

Tank Conditions

Tank size

When placing a Rainbowfish in a tank, always ensure that the tank is at least ten times the length of your full grown fish. For example a Rainbowfish that grows to about 2 inches should be placed in a minimum of 20 gallon tank. The bigger species should then be kept in a 50 to 60 gallon fish tank. The large tanks give your fish enough swimming and hiding space.

Temperature and pH

a close up of a beautiful blue rainbowfish

The best water temperatures for your fish range between 72 and 82°F. Having a thermometer in their tank is the best way to monitor for any changes with the temperature. Rainbowfish does well in waters with pH ranging from 7.0 to 8.0.


Rainbowfish love hiding in substrate especially when they get scared. Medium sized gravel and smooth river rocks are a good substrate for them. It helps to add some hollow plastic plant materials to help them hide whenever they want to.

Tank Maintenance

Check the temperature everyday to ensure that it remains constant. Monitor the filtration to confirm that it’s functioning correctly. Water testing kits are also a must have for any aquarist. The water quality should be tested at least once a week. Ammonia, nitrites, and nitrate levels should always be as close to zero as possible.

Water changes also contribute towards giving your Rainbowfish a healthy environment. Conducting 10 to 25 percent water changes every 2 weeks is recommended for Rainbowfish tanks.

The Attention Requirements of Rainbowfish

Rainbow fish are low maintenance and are a favorite for beginners. The fish rarely gets sick as long as water quality is maintained. They also don’t need to eat every day. You can be away from home for a long weekend without needing anyone to feed your fish.  

a silver and yellow colored rainbowfish swimming in their aquarium by some rocks

The fish are accustomed to going without food for days during famine periods in the wild. A Rainbowfish is the best choice for anyone looking for a pet despite their busy schedules.

Best Tank Mates for Rainbowfish

Rainbowfish are a calm non-aggressive species. They like to shoal and should be kept in groups of six or more. Rainbowfish are easy-going and will let other species live peacefully in their tanks. Here is a list of best tank mates for Rainbowfish.

Rainbowfish do not attack larger species even when they feel threatened. They will just hide behind plants and rocks when they feel threatened. They will enjoy the company of other active and peaceful species in their tank.

Larger size fish and aggressive species should not be kept with the Rainbowfish.

Health Issues

Rainbowfish are generally very immune to many types of sickness and rarely succumb to illnesses. In this section, we’ll discuss some of the most common diseases that affect the fish.

White Spot Disease

Ich Disease, also known as Ichthyophthirius multifiliis or white spot disease, is a common parasitic disease that affects many species of freshwater fish. It’s caused by tiny parasites that attach themselves to the surface of a fish’s skin and gills and feed on them. These parasites appear on your fish as white spots on their body and fins, resulting in distress and discomfort.

The best way to prevent Ich Disease is to maintain a clean and healthy aquarium environment. This means ensuring that temperature, pH, hardness, and other levels remain within the correct range for the fish species being kept. Careful tank mate selection is also important; some fish are more susceptible to Ich than others. If a fish is already infected, quarantine them in a separate tank.

Fin Rot

Fin Rot is a common illness caused by bacteria in an aquarium. It’s associated with the deterioration of a fish’s fins, scales and skin. The affected areas can become discolored, frayed or disintegrate entirely. In extreme cases, fin rot can be fatal to a fish if left untreated.

The most common cause of fin rot is poor water quality. Bacterial growth can happen when ammonia and nitrite levels become too high, or PH levels become imbalanced. Overcrowding in the aquarium can also lead to fin rot, because poor water quality is more likely when there are too many fish in a tank.

In order to prevent fin rot, it’s important to maintain a clean and healthy environment for your fish.

Feeding Rainbowfish

Rainbowfish are omnivorous and can eat both meat and vegetable foods. Commercial pellets or flakes make a good choice of food for Rainbowfish because they contain most of the essential nutrients. Supplement their diet occasionally with very finely shredded vegetables such as peas, carrots, and spinach. 

Because wild Rainbowfish eat a lot of small insects and crustaceans, they should be given live food such as bloodworms, daphnia, and larvae from time to time. Dry and frozen foods are also pretty common in pet stores but make sure to cut them into small pieces before feeding your fish. Rainbow fish are generally very small fish and feeding them large chunks of food could lead to choking.

It’s also important to note that Rainbowfish are middle to surface dwellers and prefer to feed from the surface of the tank. Fish feeding clips will allow food to be suspended from the surface of the tank. 

Any food that drops to the bottom of the aquarium is often waste and will contaminate the quality of your water if not cleaned well. Some aquarists place Rainbowfish with other fish species that feed from the bottom such as catfish, shrimp or crabs. Building a good community aquarium helps make sure that no food gets wasted.

Overfeeding is a common problem with Rainbow fish. In the wild, the fish are used to fattening up with plenty of food. Later in the year there is a food drought and they make use of their stored fats to survive.

Where Rainbowfish are kept as pets, they may tend to overfeed when they see a lot of food. The problem that then happens is that they may not experience shortage of food in an aquarium. Eventually, you may end up with overweight fish or they may develop digestive problems.

Author Profile
A woman with curly hair holding a cat.
Contributing Author & Social Media Expert

Maryna is an animal expert that has had dozens of animals in her life over the years. She has never found an animal that she didn't love immediately. It seems like every year she finds kittens that have been abandoned by their mom and she nurses them to health and finds homes for them. She contributes her vast knowledge about animals and family pets to our website and we're forever grateful to have her working with us. She's also an amazing graphics designer and has designed all of the social media images that we use across all platforms.