Owing to its small size and tendency to stay close to a chosen refuge, P. porphyrea is suitable for relatively modest-sized aquariums in the range of 70 to 100 liters. Keep in mind, however, that the smaller the tank (i.e., the more compressed its territory), the more challenging it becomes to keep the magenta dottyback with other species. If kept in a nano system, it would likely need to be the lone fish occupant.
Aquascaping should include ample rockwork, not only so the dottyback is sure to find a nook that suits its fancy, but also to provide plenty of refuges for tankmates that might need to evade its line of sight and possible wrath.
The magenta dottyback is generally considered a good candidate for reef systems, demanding little in the way of open swimming space and being totally inoffensive to corals and other sessile invertebrates.