1) Change 2) Convert certain water 3) Desalinate 4) Desalinise 5) Desalinize 6) Distill brine from 7) Make drinkable 8) Make ocean water drinkable 9) Make potable 10) Make sea water drinkable 11) Make sea water potable 12) Make seawater drinkable 13) Make seawater potable 14) Make the Pacific drinkable 1) Desalinate 2) Desalinise 3) Desalinize 
to remove the salt from (esp. sea water), usually to make it drinkable.