Abstract: A water filtration system incorporating a fluid flow meter has a modular turbine casing assembly in which a turbine is located between upstream and downstream casing elements of identical shape and formed to be stacked so as to trap the turbine in between. The turbine is magnetized and rotation of the turbine is monitored electronically with a reed switch having a lead wire which is positioned proximate to the turbine to sense fluctuations in a magnetic field created by the turbine on rotation of the turbine. The reed switch housing itself is disposed at a location remote from the turbine. The system further includes processor for calculating an adjusted accumulated count data for low volumetric flow rates which are less than a predetermined threshold value. Advantageously, the invention can be used to reliably measure very low flow rates with very little power drawn.