Previous papers based on earlier research displayed that the dissociates inhibitor specie is the active form for the polymers and phosphonates scale inhibitors. This article elaborates on the inhibitors evaluated and considers the impact of ionic strength and temperature on the inhibitor speciation via the dissociation constants and PKa's. Studies of scale inhibitor dosage inhibition are embedded that quantify the relative efficacy of inhibitor species. A description of the the test methods and their development are included alongside the data evaluation methods.