User blog comment:Miskos3/Fairy Tail Episode 256: Tartaros arc: The Final Duels, Review/@comment-25111584-20151024095646/@comment-7418318-20151024102236

We've never seen Juvia's water disappear once she's knocked unconscious, so I don't think her magic works the same way.

And I doubt the water was part of Alegria. It was probably just a water tank filled with natural water (or whatever liquid that was) that ruptured due to Cube transforming into Plutogrim, instead of any magical occurance.

Alegria was already finished by the time the liquid came through the wall.