A low energy fluid purification system and method of implementation including some embodiments having a vacuum-rated first chamber placed in or near a body of water with higher temperature near the surface and lower temperatures at greater depths. The vacuum-rated first chamber holds a quantity of non-potable water and a low pressure area less than or equal to the water's vapor pressure. Vaporization occurs when the higher temperature surface water is brought into contact with the low pressure area. A tubular vapor transport passage allows the vaporized water to pass to a lower temperature and lower pressure condensation chamber. The lower temperature condensation chamber is cooled by lower temperature water from a selected depth below the surface. As the temperature of the vapor lowers, the vapor will condense. This condensation is collected as a quantity of potable water. Additional embodiments and methods are also provided.