It looks like I haven't said everything necessary.
I KNOW it is the jug on the ground floor because there is a jug on the top floor that works with the sink.
The item identification number is different as well (the numbers you see when you right click on an item).
I'll put the two numbers here when I get a chance.
Jug: 1935
Weird Jug: 3732
Another note, the weird jug has a destroy instead of a drop option.
Found the problem. The jug isn't tradeable, I guess the devs used the wrong id.
Where Found:
Search chests in Peer the Seer's house in Rellekka.
Item Uses:
Used for The Fremennik Trials quest.
Notes:
Used in obtaining a 4/5ths full bucket. If lost or destroyed, it can be retrieved by searching the chests again. A Jug is an item that can be filled with water. Wine can also be made in jugs with water.
Examine Information:
This jug is completely empty. It has a 3 painted on its side.