The girls' powers are as follows: Cleo can manipulate water, Emma can freeze water, and Rikki can boil water. In Season 2, they gained weather control as well. Cleo can manipulate wind, Emma can now draw moisture from the air to freeze and Rikki can draw forth lightning which catches things on fire.
Nickelodeon advertised a 15 minute sneak peek two weeks before the show was aired.
Cariba Heine hired a professional trainer to help improve her swimming while auditioning for the part of Rikki.
The actresses put full cream milk in their eyes to help them keep their eyes open underwater.
The mermaids' wardrobe frequently follows a color scheme. Emma: white/blue, Cleo: pink/purple, Rikki: black/red.
Angus McLaren does not appear regularly in season three due to filming Packed to the Rafters.