1. A method for determining the effectiveness of a fluid treatment process, the method comprising the steps of: a. acquiring a first sample of a fluid to be treated prior to treatment; b. analyzing the first sample with particle imaging for particles in the first sample, including obtaining color images of the particles in the first sample; c. acquiring a second sample of the fluid after the fluid has been treated; d. analyzing the second sample with particle imaging for particles in the second sample, including obtaining color images of the particles in the second sample; e. defining a particle image color indicative of particle death; and f. comparing the color images of the particles in the first sample with the color images of the particles in the second sample to determine a change in particle image color corresponding to the defined particle image color.