Recently a new method, SEnsing of Phage-Triggered Ion Cascade (SEPTIC) was proposed for the rapid detection and identification of bacteria via the electrical field caused by the stochastic emission of ions during phage infection. In this Letter, we present linear network theoretical considerations about the detection limits of the method. The considerations are based on our published data of the E. coli detection experiments and on the assumption of a linear response between the number of bacteria and the measured power density spectrum of the fluctuation-signal. Some practical limits of the detectability of the present agents with possible noise measurement arrangements are discussed in this paper. The calculations indicate that the detection and identification of a single bacterium can be achieved with natural (wild) phages with reasonable efforts within a time window of 10 minutes.