Introduction to Your Pet Freshwater Rainbowfish

Posted by Big Al's on Dec 9, 2016 9:56:19 AM


If you’re looking for a colorful new addition to your home aquarium, it might be easy to pass by the juvenile rainbowfish. Its drab coloring is at odds with its promising name. It may be a bit more expensive than its more popular barb and tetra peers. Don’t be fooled by the lack of color or dissuaded by the higher price; this fish will soon grow into its name and become the shimmering jewel of your tank.

Types of Rainbows

Rainbows come in many varieties, including the true rainbowfish of the family melanotaenidae and the related pseudomugilidae and atherinidae families. Popular tank species include:

  • Banded rainbow
  • Boeseman’s rainbow
  • Dwarf Neon rainbow
  • Lake Kutubu rainbow
  • Red rainbow
  • Threadfin rainbow

All rainbowfish will be happiest when kept with at least five others of the same species. New members can easily be added to an existing school.

Tank Setup

Rainbows are found in New Guinea, Australia, Southeast Asia and Madagascar. They are extremely adaptable, but most at home in tanks between 22-28°C (72-82°F). They can tolerate great variety in hardness and pH values, but most species prefer medium to hard water with a slightly alkaline pH. The quality of the water seems to be a much more important factor. Clean, well-filtered water with minimal waste and high oxygen content is best for keeping fish healthy, active, bright and more inclined to breed.

To keep water clean, use an internal power filter. These provide plenty of circulation while filtering out impurities. Larger tanks (40-50 gallons or more) may require an external canister filter as well as an internal power filter. Water should also be changed frequently; a weekly water change of 30 percent is ideal for rainbowfish, although their needs can be balanced with those of other fish in the tank.

Tank Mates

Rainbows are generally peaceful, although males may show harmless aggression when spawning. These shoaling fish should be kept in groups of five or more. While they are not aggressive towards other fish, they are very active and quick. Smaller, more timid companions may find it difficult to compete for food against larger varieties. Many types of fish coexist peacefully with rainbowfish, including:

  • Bottom feeders: loaches, corydoras catfish
  • Algae-eaters: bristlenose catfish, true Siamese algae eater
  • Mid-water and upper-level shoaling fish: barbs, rasboras, danios, larger tetras


Rainbows are not picky, but they thrive on a varied diet. In the wild, they consume mainly insects and larvae, but they are omnivores and also enjoy vegetable material. Your fish’s diet could include:

  • High-quality flake, granular or pellet food for omnivores or herbivores
  • Meaty food such as mosquito larva, daphnia, brine shrimp and cut earthworms
  • Fresh vegetables

These fish are primarily surface feeders, and may not eat food that sinks to the bottom. To keep the tank clean, give small amounts of food several times a day. Adding a bottom-feeder or two to your collection can also improve water quality and reduce food waste.

Rainbowfish add a striking flash of color to any tank. They are peaceful, active and hardy, making them a pleasure to keep. Find everything you need for this beautiful fish in our online store.