I've seen two different things, Jonathon Denus, and Jonathon Denis. So either one of those.
Claire Holt
Ash's real name from H2O: Just Add Water is Ashton Taylor.
The real name of Kim from H2O is Cleo Massey. She is an Australian actress known for her role in the television series H2O: Just Add Water.
Will's real name in "H2O: Just Add Water" is Luke Mitchell.
Jonathan
I've seen two different things, Jonathon Denus, and Jonathon Denis. So either one of those.
The real name of Cleo on H2O is Phoebe Tonkin.
Bella's real name from H2O is Indiana Evans.
The real name of the actor who played Zane in H2O: Just Add Water is Burgess Abernethy.
Claire Holt
Ash's real name from H2O: Just Add Water is Ashton Taylor.
The real name of the actor who played Elliot Gilbert in "H2O: Just Add Water" is Trent Sullivan.
Charlotte's real name in the show "H2O: Just Add Water" is Charlotte Watsford.
Her real last name is Byrnes and her real name is Brittney,Brittney Byrnes
Cleo's real name in H20 is Phoebe Tonkin
Indiana Evans :D