Originally found in the rivers of South America, the Discus (Symphysodon discus or S.heckeli) is considered the “king” of the freshwater fish by many hobbyists. Up until the early 80’s, nearly all Discus were captive caught and considered fairly difficult to keep, requiring very soft water with a pH from 6.0 to 7.0 and warmer temperatures in the mid 80’s F. They were also notorious for refusing to eat most prepared aquarium foods except bloodworms and, for some reason, frozen beef heart! Starting in the 80’s, breeders in the US, Europe, and Indonesia started to selectively cross breed Discus to intensify colors and patterns until the two original types were replaced by 100’s of different color morphs. The breeders also developed different color patterns with “snakeskin” scale patterns, multiple stripes, spotting and even solid body colors with exaggerated fin development. In addition to all the color morphs, the selective breeding also developed a hardier fish capable of withstanding many different water parameters. When purchasing Discus, it is best to determine how they were raised to see if you can match those conditions.
Many breeders will claim that to maximize the growth and productivity of the Discus, you need to keep them at 85-90F and do as much as 100% water changes every day! While this regimen certainly can work, it is much more work than most hobbyists are comfortable with to maintain their aquariums. While keeping the fish at higher temperatures lessens the chance of parasite infestations, in a properly maintained aquarium and with the use of quarantine procedures, this should not be a reoccurring problem. Temperatures in the upper 70’s and low 80’s will be fine and will maintain the health of the Discus. The key is to maintain a constant temperature to avoid undue stress from changing temperature. The Discus still prefer a meaty-based diet, but are more accepting of other prepared foods including flakes and pellets. Keep in mind that they are members of the cichlid family and will show aggression and are perfectly capable of eating smaller fish. To make the Discus feel at home, the aquascaping should include lots of broad leaf plants (real or fake) and pieces of driftwood that imitate roots and fallen branches. The Discus will spend most of their time hovering in the plants or under the driftwood and generally avoid really bright lights. It is best to house the Discus with other fish that are not too aggressive or known as fin nippers to avoid any constant aggravation.
If you are lucky and happen to have a pair of Discus that decide to spawn in the aquarium, be prepared to find the pair vigorously defending the eggs and chasing all the other fish into the corners! Discus make good parents and actually secrete an “edible slime” that the hatchlings will eat from the sides of their parents. After carefully guarding the fry for 10-14 days, the parents will chase them off and get ready to spawn again.
With the success of farm raised Discus, perhaps the most difficult part of keeping Discus is deciding on the color morph, type of pattern or body style to keep. Most Discus are sold as juveniles of approximately 3-4” diameter but can grow well over 10” in diameter and are one of the few fish that become more colorful the larger they get. They are demanding of good water quality with proper filtration to ensure their health.