It might just be from the tank evaporation, or even coming down one of the cords. Or even a bit of spilled water that is slowly working its way out.
The back right is the compartment with all the cords coming into it correct? Pull the power center out and see if you have any moisture inside that area, and check your cords to see if any show any crystalline salt at all.
Edited by Crazy Tarzan - January 28 2014 at 6:19pm