Red-tailed black shark

In home aquaria, redtail sharks prefer a pH between 6.8 and 7.5, a temperature between 22 °C and 26 °C (72 °F and 79 °F) and water hardness between 5 and 15 dH.

Typically they are aggressive chasers, but will rarely bite or harm other fish. Individual personalities vary greatly—some are calm, while others are rather aggressive towards tank mates. They are bottom dwellers and like lots of dark hiding places. They get along with gouramis, barbs, danios, and catfish, and they do well with other sharks when they are young.

When two redtails cohabitate, they may become territorial with each other as they mature. One shark will become dominant and will continually chase and harass the submissive shark. Larger groups of five or more, surprisingly, tend to get along much better than two or three, as they will establish a stable hierarchy; such a group will require a very large heavily planted aquarium, however.

Redtail sharks are considered compatible in some community tanks when young but when mature they may chase docile or peaceful fish who present a large target (such as the Metynnis argenteus, or "silver dollar" fish); similar sharks can be chased but sometimes resulting in no physical damage. Redtails do not typically bite or injure other fish, but will chase them. They will mostly chase fish away from their territory and then retreat; therefore, it is important to ensure the aquarium is large enough to allow the redtail some space to call its territory. Aquariums should be at least 170 litres (45 gallons) when a red tail shark is mature but when young probably a 10–20 gallon aquarium or larger for a comfortable community. Redtails are bottom dwellers. Despite this, it is often reported that they do not generally harass loaches, such as Chromobotia macracanthus, and may even exhibit schooling behavior with them.