Abstract: An exemplary device and method for removing undesired substances from original water comprises a cooling circuit for cooling the original water to or below approximately Zero degrees Celsius, whereby the saturation level of the undesired substances in the original water is exceeded, thereby causing segregation of the original water into purified ice, undesired precipitated solids, and a waste liquid containing the remaining undesired substances (soluble salts). Means for removing the waste liquid from the purified ice, a heating circuit for melting the purified ice into purified water, a reservoir having an inlet for receiving the original water and an outlet for dispensing the purified water, and a first water purity monitor disposed adjacent the outlet for monitoring a first purity level of the purified water are provided.