Many human activities are harmful to this species, including dumping toxic waste (from the mining and forestry industries), fishing and collecting for the fishkeeping market.
Like all fish, the angelfish is sensitive to water quality; it needs water that is clean and pollution free.
Living in groups of four to six individuals, angelfish are highly territorial. Freshwater angelfish form pairs when they reach adulthood; however, the belief that angelfish are monogamous is not entirely true, as they are occasionally observed mating with other partners. It is important to avoid keeping a pair of angelfish in too small a volume of water (aquarium of less than 100 litres), as this will stunt their growth and encourage aggressive behaviour.
While freshwater angelfish are less aggressive than other cichlidae, they should not be made to share a habitat with small fish (less than 4 cm). It is also important to remember that it is better to avoid putting them in the same space as other aggressive fish like cichlidae because their fine fins are vulnerable to biting and nibling.
In addition to being spectacularly beautiful, angelfish love playing with their own kind (especially juveniles) and will make a beeline for the person who feeds them.