The main challenge in the management of a sequencing batch reactor, for the biological treatment of urban and industrial wastewaters, is to ensure stable treatment efficiency under highly variable influent quality and quantity. To cope with this challenge, online instrumentation is fundamental, since it allows to characterize both influent variability and process efficiency. The more the online data are closely correlated with influent quality and SBRs treatment capacity, the more straightforward is the implementation of control strategies based on these data. In this paper, two monitoring techniques are described, which allow to obtain influent-related and process-related data: set-point titration and UV spectrophotometry. Despite the very different measuring principles, both techniques were successfully applied to SBRs monitoring and control leading to comparable results.