The aquarium opened in 1985 after 10 months of construction. Tarlton developed a new method of building an acrylic tunnel by taking large sheets of clear acrylic, cutting them to size and heating them in an oven until they took the shape of the mould. Some of the sheets weighed over one tonne. Because of the refraction caused by light travelling through water, and the acrylic sheets used in the creation of the tunnel, the fish appear to be one third smaller than they are.