H2O: Just Add Water - Season 3 - Eps 25: A Date With Destiny
Cleo discovers a comet is causing fish to flee the waters around Mako Island. The girls find a way to restart the message in the Moon Pool and discover the comet will collide with earth. Sophie meets Ryan and with Zane's help they join forces to remove the crystals from the Moon Pool.
About H2O: Just Add Water

Title: H2O: Just Add Water
First Air Date: 2006-07-07
Last Air Date: 2010-04-16
Status: Ended
Rating: 7.812/10 (from 653 votes)
Language: EN
Seasons: 3
Total Episodes: 78
Network: Network Ten
Genres: Drama, Family, Sci-Fi & Fantasy
Production Companies: Pacific Film and Television Commission, Jonathan M. Shiff Productions, Network Ten, ZDF
Synopsis
H2O: Just Add Water revolves around three teenage girls facing everyday teen problems with an added twist: they cope with the burden of growing a giant fin and transforming into mermaids whenever they come in contact with water.
Cast

Phoebe Tonkin
Cleo Sertori

Cariba Heine
Rikki Chadwick

Indiana Evans
Isabel "Bella" Hartley

Luke Mitchell
Will Benjamin

Burgess Abernethy
Zane Bennett