Tometes baileyi is one of several large pacu species in the genus Tometes, a group of impressive herbivorous serrasalmids found in the Amazon and Orinoco drainages. It is a powerful, deep-bodied fish capable of reaching 50 cm or more in optimal conditions, making it one of the largest commonly encountered members of the pacu family available to specialist aquarists. In the wild it feeds on aquatic macrophytes, algae on rocks in rapids, and fallen fruits.
This species demands very large aquariums — 1500 litres minimum — with industrial-strength filtration and very frequent large water changes. The water should be soft and warm. Live plants are not practical in a Tometes aquarium as they will be consumed rapidly. The tank should feature robust hardscape and open swimming space to allow expression of its powerful, active swimming behaviour.
Tometes baileyi is peaceful towards other large fish and is compatible with Myloplus, Myleus, large Brycon, and peaceful large cichlids. It should not be kept with piranha species or aggressive large predators. Due to its sheer size and demands, it is strictly a fish for dedicated advanced specialists or public aquariums.