can a moon pool really turn あなた into a mermaid on a full moon?

I don't think so but it might be possible

no because there is n moon pool i was watch H20 just add water behind the scenees

The moon pool on the 表示する is fake. And they made it, put it together. But maybe, just maybe, if あなた could find または make a moon pool from moon rocks, fill it with sea water, and get in it on a full moon overhead, then we will sea if it works. If あなた will be a mermaid.