A water purification apparatus (10) which includes at least one emitter (12) and a processor (14). The emitter (12) is for emitting an electromagnetic wave having a specific frequency through water (14), with the emitter (12) also being configured to propagate the emitted wave through water (14). The processor (16) is arranged in communication with the emitter (12) which processor (16) is configured to automatically regulate a frequency of the electromagnetic wave emitted by the emitter (12) so that the specific frequency or harmonic components of said wave is similar to a resonant frequency of a particular impurity typically found in water (14) in an attempt to destroy the impurity.