The present invention relates to systems and methods for reducing microbial contamination, particularly biofilm formation, in plumbing fixtures. In particular, the invention provides a computer implemented method for counteracting biofilm formation in a plumbing fixture, and a plumbing fixture in which the method may be applied. The method comprises: monitoring a parameter relating to microbial presence within the plumbing fixture, for example using a sensor; determining a level of risk related to biofilm formation based on the monitored parameter, for example based on sensor data; and in accordance with the determined level of risk, applying a countermeasure to the plumbing fixture in order to counteract biofilm formation.