An embodiment provides a method for determining total iron content in real time in a high purity water system including the steps of: assessing total iron content in each of a plurality of water samples having differing total iron content values; measuring, with a high-intensity turbidimeter, the turbidity values associated with each of the plurality of water samples; identifying a linear relationship between total iron content and turbidity of the plurality of samples; providing a high-intensity turbidimeter positioned in a water conduit of the high purity water system which is responsive to the turbidity of the water system; measuring the turbidity value of the water in real time, with the high-intensity turbidimeter, to generate a continuous data stream representative of the turbidity value; providing a processor programmed with the linear relationship identified between total iron content and turbidity of the plurality of samples; and calculating total iron content of the water in real time by transforming the measured turbidity values of the water using the linear relationship identified between total iron content and turbidity of the plurality of samples by use of the processor. Other embodiments are described.