vat with purple crystal in mines.

[Chuck]

So i cant do a good job describing this, but i go into the mines, and some way down i find an empty potion, and a semicircle cauldron that i am pretty sure i have to pour something into. There is a purple crystal in the vat, on the background. So not a physical crystal i can touch but just some texturing on the back of the vat. I assume, because the crystal is purple, i need something like polymorphine to pour into it, but i tried that and nothing happened. what do with it?

[Nova]

water i think, you can look up furyforged noita puzzles to see the answers to all of them

[Perseus]

Hint 1 : Search the direct vicinity of where you found the empty flask.

Hint 2 : Look behind the wood wall to the right of where the flask was, there's another vat.

Solution : Transfer the contents of the already filled vat to the empty one.