This show first premiered in July 2006. It ended up having three seasons with a total or 78 episodes. It starred three teenage Australian girls, Rikki Chadwick, Emma Gilbert, and Cleo Sertori who find themselves stranded on Mako Island. They end up wandering into a mysterious pool of water just as the full moon passes over. They all stare into the moon and without them knowing, magical things happen. They soon are rescued and return to their normal lives, but soon figure out that their lives are completely changed. They soon discover that ten second after coming into contact with water, they turn into mermaids! The show covers them figuring out how to live with their new lives, while also keeping it a secret from everyone. Exciting and interesting times are in store for these three!
You can find all of these episodes on Netflix.