Discus Fish Care Guide | Planted Aquarium

Discus Fish Care Guide | Planted Aquarium

The discus fish (or Symphysodon) is a freshwater fish of the cichlid genus. The fish’s common name is derived from its flattened shape.

Unlike many cichlids, the discus thrives in groups, is generally calm, and tends to be shy with other species. Brightly colored and often intricately patterned, the discus fish is typically between 4.8–6.0 inches in length.

Although discus fish can be challenging to keep, especially in a mixed tank, enthusiasts prize the fish for their striking appearance and incredible ability to change color.

The discus fish is native to the Amazon river in South America. The blue discus is native to the eastern Amazon basin, the green discus is native to the western Amazon basin, and the red discus is native to the Rio Negro area.

This species is challenging to keep in a mixed-species tank due to the discus fish’s low pH, high mineral content, and warm temperature needs. Captive discus fish have more vibrant colors when water parameters are well-maintained, even though the fish adapt better than wild species to water fluctuations.

Decorate the discus fish’s tank with driftwood to replicate the fallen trees in branches found in the species’ native habitat.

Discus fish get along well with other species, but keeping a mixed-species tank with discus can be challenging because the fish has strict tank condition requirements. A group of discus fish makes an attractive addition to any aquarium due to the fish’s flat, rounded shape and vibrant coloring.

Discus fish have four primary jewel-like colors and the fish display a variety of markings and patterns, which enthusiasts highly prize. Heckle discus are typically pale yellow with three vertical stripes of the same color, with one stripe running through the eye. Brown discus have nine vertical stripes, while blue and green discus have red dots.

Many of the more brightly marked discus variations result from hybridization and don’t exist in the wild. Complete coloring emerges as the fish matures, and the fish change color according to their environment and other factors.

Bright colors and vivid markings on specimens under 2 inches long may result from hormone supplementation, and if this is the case, the colors fade over time.

While the discus fish’s flat sides and rounded shape give the species some resemblance to angelfish, discus fish lack the angel fish’s characteristic extended fins.


Discus are peace-loving fish that thrive when they can swim slowly around an aquarium in a group. When intimidated by larger, faster, or more aggressive fish, discus tend to hide in plants or caves. Discus fish are active in the day and sleep at night.