It's a well-known legend: we all have our exact double. He or she could be living in our neighborhood or maybe in China . "Water and Salt" makes focus on this idea: The stories of a lawyer and his double (a fisherman), intersect with a particular result.
This movie was almost entirely filmed in Mar del Plata, and has a great photography. Nice filming places and sound is OK (Argentinian movies' sound is a problem). Spregelbroud and his silences in some parts of the film say a lot. He can tell us what his feelings are, with no need of explanation.
So, Watch it and then try to answer this question: ¿who is the REAL double?