 The waterworks' turbine and pumps were initially used to get water from the Schuylkill River for the exhibits, but this untreated water proved to be too polluted for the fish, and the aquarium switched to using city water.All of the machinery was removed from the two powerhouses in 1912, and they were eventually refitted as the exhibit halls for the aquarium, the larger () being used for freshwater fish and the smaller () for seawater fish.The buildings required very little structural change, and the flat roofs, previously used as plazas, provided space for skylights to illuminate the exhibits.