The tight control of pH prior to coagulation is the first phase of a longer term comprehensive research programme. Due to the complex interactions between so many variables it is a necessary precursor to other work. For example, coagulant dose control by means of a streaming current detector (SCD) or feedforward algorithm, which are other areas of on-going investigations, are heavily influenced by pH. Therefore eliminating the effect of this variable via good process regulation is an important and necessary development.