Abstract: A fluid treatment device including a source of electrical voltage having a first and second terminal, a pulse generator connected to the first terminal and the second terminal and outputting a pulsed voltage wave signal between a third terminal and a fourth terminal, at least one coil positioned adjacent at least one fluid conduit, being electrically connected to the third and fourth terminals and at least one capacitor also being electrically connected to the third and fourth terminals to form a first circuit with an inductance L, a capacitance C and a resonant frequency. The pulse generator is arranged to generate a pulsed voltage wave with a frequency approximately equal to the resonant frequency. A further circuit element is arranged to cause the voltage pulse reaching the coil to repeatedly, alternate between a period of pulsed voltage at the frequency and a period of zero voltage, with each period extending for a time in a range of approximately 2 to 33 milliseconds.