Complex sentence: Following the release of "Good Morning Sunshine", Aqua decided to concentrate on their second album, and on touring around in Australia, to very moderate success, and marked the end of a period Aqua's fans dubbed the "Aquarium age".
Split into simpler sentences: Following the release of "Good Morning Sunshine", which achieved limited success, Aqua decided to concentrate on their second album, and on touring around Australia. This marked the end of a period Aqua's fans dubbed the " " Aquarium "age".