i noticed this and i think its dumb that they are not damaged by the water in potions and water filled cauldrons.

possible duplicate of #202? (maybe turn that one into a more generic issue and then we'll have one issue for this whole thing?)

Water-filled cauldrons do not affect the hydrophobic origins because they are not considered by Minecraft to be filled with water. This is also why breathing in them does not work as a Merling. I have no intention to change this because I want to stay consistent with the vanilla mechanics of the cauldron (should vanilla change this at some point, I will too).

Drinking water bottles hurts the hydrophobic origins since version 0.7.0. I will look into the other potions, but for that I will leave the other issue MineRobber9000 linked open and close this one since it's a duplicate.