The BEST Episodes of H2O: Just Add Water
Every episode ever - ranked by fan votes!
Last Updated: Aug 4, 2019
Season One: The lifes of three girls living on the Australian Gold Coast are changed forever. When Cleo, Emma and Rikki stumble upon a pool inside the dreaded Mako Island, a full moon transforms them and the next day they start turning into super powered mermaids! With the help of friend Lewis, the girls manage to control their powers and hide their secrets. But it becomes difficult with maddening full moons, nosey scientists and local bad boy Zane going on a quest to find them! Season Two: Following the incident with Dr Denman and the Lunar Eclipse, Emma, Cleo and Rikki want to go back to their normal lives. But when the full moon comes back, all three girls have a dramatic power change! Without Lewis, they could destroy themselves. But their friend is trying his best to help them, despite his relationship with geeky Charlotte. But Charlotte proves to be more of a threat when she learns about her grandmother being a mermaid and stumbles into the moon pool and becomes a mermaid herself!
#1 - A Twist in the Tail
Season 1 - Episode 26
Dr. Denman sets up a trap for the girls at Mako Island and Zane is forced to decide who he should be helping.
8.60 
#2 - Three's Company
Season 2 - Episode 24
More friction arises, this time over Lewis' birthday party. Charlotte takes control and drives Rikki away from the party. However, things go out of hand and it is up to her to save the day.
8.55 
#3 - Unfathomable
Season 2 - Episode 26
A unusual and rare planetary alingment is set to cause the full moon to remove a mermaids powers if they enter the moon pool! Charlotte shows immunity and tries to reveal the girls' secret before Lewis takes her to Mako Island. The girls follow and a battle erupts. But who will win?
8.54 
#4 - Treasure Hunt
Season 2 - Episode 11
In need of cash, Rikki decides to go and searching for a lost statue with a huge reward. But she lies to Emma and Cleo, which causes danger when Rikki is knocked out!
8.44 
#5 - And Then There Were Four
Season 2 - Episode 21
Charlotte's stubborn nature and thirst for knowledge leads her to Max, who confirms her suspicions and leads her to the Moon Pool. Lewis meanwhile is having trouble trying to keep their relationship together.
8.37 
#6 - The Gracie Code (2)
Season 2 - Episode 20
Charlotte demands answers to why Lewis is hanging out with the girls so much. She starts to believe an excuse from Cleo, but then a discovery from inside Max's research brings her to the secret! Meanwhile, Ash decides to help Emma with her "fear of water."
8.34 
#7 - Into the Light
Season 3 - Episode 18
Rikki fears Ryan's explorations on Mako Island will uncover their secrets but Cleo and Bella discount her concern. She almost goes too far trying to stop Ryan from discovering the crystals in the Moon Pool.
8.21 
#8 - Riding for a Fall
Season 2 - Episode 9
Emma has to take Eliot for horse riding lessons and the competitive perfectionist tries to be better than the instructor. Meanwhile, Lewis double dates with Charlotte and Cleo.
8.21 
#9 - Graduation
Season 3 - Episode 26
Sophie and Ryan damage the Moon Pool in their efforts to obtain the rare crystals. The girls improvise and use their own magic to prevent the impact of the comet and a planet wide catastrophe. Rikki, Cleo and Bella graduate with a surprise.
8.20 
#10 - In Hot Water
Season 2 - Episode 7
Everyone is shocked when Cleo is fired at the Ice Cream Stand, and even more so when Lewis takes her place! Rikki and Emma strike back at him but end up going too far
8.19 
#11 - Bubble, Bubble, Toil and Trouble
Season 2 - Episode 22
The girls decide that they should accept Charlotte, and the four work together when they need to join the volleyball team to avoid failing Physical Education.
8.19 
#12 - Wrong Side of the Tracks
Season 2 - Episode 8
Zane is curious by Rikki's reluctancy to reveal where she lives. So one day, he eventually convinces her to reveal her home: a trailer park with her grouchy father.
8.18 
#13 - Queen for a Day
Season 3 - Episode 20
Zane installs Sophie as head of staff at the cafe. Bella develops a sneezing allergy that also accidentally triggers her powers. Sophie seizes on the problem and looks to fire Bella and the band.
8.15 
#14 - Breakaway
Season 3 - Episode 19
Will competes in the Free-Diving Championships but afterward chooses to break from the sport and shrug off Sophie's influence on his life. Rikki sees Sophie kissing Zane at the event and breaks off their relationship.
8.13 
#15 - Pool Party
Season 1 - Episode 2
Annoying Miss Popularity, Miriam, is having a pool party and the girls want to go. But being around water is risky, especially when Zane tosses Cleo into the pool. Lewis is the only one around to help so he finds out their secret.
8.12 
#16 - Crime & Punishment
Season 3 - Episode 12
Rikki receives counterfeit money at the cafe and is held captive by criminals on a boat. Bella and Cleo are forced to reveal the trio's secret to Will so they can rescue Rikki together.
8.11 
#17 - Kidnapped
Season 3 - Episode 8
During a full moon, the girls stay at Cleo's and Bella is attacked by the water creature. At the same time, Will decides to return to the moon pool after making the connection between his previous encounter with the moon pool waterfall and the timing of the full moon.
8.11 
#18 - The Denman Affair
Season 1 - Episode 8
Lewis is offered a great job with a marine biologist, but the girls are concerned that his interest will cause him to reveal too much information
8.10 
#19 - Under the Weather
Season 1 - Episode 17
The girls have to fake sick as a result of a thunderstorm, so their secret won't be discovered at school. But their 'sickness' attracts the attention of doctors.
8.09 
#20 - Dr. Danger
Season 1 - Episode 25
It's time for Emma's family's annual vacation trip, but she can't go as the risks are too high. But all her excuses don't go very well with her family. Meanwhile, with the return of Dr. Denman, Zane is closer than ever to cracking the girl's secret.
8.09 
#21 - The Dark Side
Season 3 - Episode 16
Rikki's frustrated by the water attacks and goes to Mako Island on a full moon to confront the strange force in the Moon Pool. With Cleo and Bella delayed, Will pursues her and discovers she's been affected by the experience.
8.09 
#22 - Sea Change
Season 2 - Episode 25
Angry over the short friendship with the girls, Charlotte forces Lewis to choose between her and his friends. This results in Cleo to feel isolated and she runs away and gets lost. When he is informed, Lewis must make up his mind: Cleo or Charlotte?
8.07 
#23 - Too Close for Comfort
Season 3 - Episode 24
Don gets a second job at the Marine Park on the Pirate ship and outshines Cleo, threatening the future of her Dolphin show. Bella and Will find difficulty trying to connect with each others' interests.
8.07 
#24 - Love Potion #9
Season 1 - Episode 24
With the school dance coming up, Emma and Cleo hope Byron and Lewis will ask them out. Meanwhile, Miss Chatham and Lewis are arguing about which is more important, magic and science.
8.05 
#25 - The One That Got Away
Season 2 - Episode 3
Rikki tries to avoid Zane when he comes back, but needs his help after an incident with a speedboat. Meanwhile, Charlotte continues to flirt with Lewis and Cleo worries for their secret.
8.04