<Li> Mako: Island of Secrets </Li> <Li> H O: Mermaid Adventures </Li> <P> H O: Just Add Water, also known as H O, is an Australian dramatic fantasy television programme for children and teenagers created by Jonathan M. Shiff . It first screened on Australia's Network Ten and runs in syndication on channels in over 120 countries and has a worldwide audience of more than 250 million . It was filmed on location at Sea World and other locations on the Gold Coast . The show revolves around three teenage girls facing everyday teen problems with an added twist: they're mermaids with powers over water . </P> <P> Only two series with a total of 52 episodes were originally planned, but due to popular demand, a third series was filmed . Series one premiered in July 2006, followed by series two in September 2007 . Series three first aired in the United Kingdom in October 2009, with the Australian premiere occurring in May 2010 . </P>

H20 just add water where is it filmed
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