Method and system for testing sodium dimethyldithiocarbamate in water

A water testing system having a water sample container that is adapted to retain a water sample, a color indicator container that is adapted to dispense a color indicator which is adapted change the color of the water sample when the water sample contains DTC, and a colorimeter that is adapted to automatically determine a blank value and the concentration of sodium dimethyldithiocarbamate in the water sample. A method for determining the concentration of DTC in a water sample comprising providing a water testing system, placing the water sample in the water sample container, placing the water sample container in the colorimeter, automatically determining a blank value, adding the color indicator to the water sample, placing the water sample container in the colorimeter, and automatically determining the concentration of DTC in the water sample.