Despite its destruction in the Season 3 of H2O: Just Add Water, the Moon Pool somehow becomes active once again in Mako: Island of Secrets where a young boy named Zac Blakely becomes a merman when he falls into it (although it is later revealed that he was a natural born merman, and his fall into the Moon Pool merely broke a spell that prevented him from growing a tail). Later, his girlfriend Evie McLaren would accidentally become a mermaid as well.
In Mako: Island of Secrets, the Moon Pool is completely different in appearance than how it appeared in H2O; the original entrance from land has disappeared, instead it was relocated to another side of the cave. According to Rikki in the Season 3 of Mako: Island of Secrets, the Moon Pool's new appearance has been around since she and the others left, implying that they are somehow responsible for its remodeling.
As mentioned above, the Moon Pool has the power to turn normal people into merpeople when the Full Moon passes over. During this time, any human who jumps into the pool will be turned into a mermaid or merman, and given special individual powers. The Moon and the pool generate different magnetism and effects depending on the moon's phases and the planetary alignments.
Special Planetary Alignment
During a rare planetary alignment, the moon will increase the powers of a mermaid or merman, granting them weather powers if they are in the Moon Pool during the alignment.
The Moon of Fifty Years
At every fifty years another planetary alignment takes place. If a mermaid or merman is in the Moon Pool during this alignment, they will lose all of their mermaid powers, and will return to their original state as a Human. It is not known how that special magical force could affect a human, or affect her/him at all.
During a Lunar Eclipse, any merperson who is in the Moon Pool will lose their powers for 12 hours. After that period, they will return.
These effects apply only to human-turned-merpeople, because they became merpeople by the Moon Pool, and subsequently, the Full Moon reacts and can increase or remove their powers and mer-form according their alignments.
- The Moon Rings store moonlight and can be used to simulate a Full Moon.
- These places were formed after a collision with a comet, the latter forming Mako Island, and one of the pieces formed another moon pool in Ireland.
- A potion of full moon magic amplified by fifty which causes magic-made merpeople to lose their mer-form, has to be used in the Moon Pool during the Full Moon.