The good side of mini aquariums is that anyone can have one. The monetary investment is small, and the space requirements so minimal that virtually everyone can find a place for one. College students in dorms, nursing home patients, apartment dwellers, even the most crowded of school classrooms all have space for a mini aquarium. Often apartment building 'no pet' rules don't apply to fish. Fish are very relaxing to watch, and can provide an opportunity for children to care for a pet in situations where larger pets are not allowed.