The present application provides a method of evaluating media effectiveness in a gas turbine engine. The method may include the steps of receiving a baseline media effectiveness rating, receiving a media replacement cost, receiving a number of operating parameters from a number of sensors, based at least in part on the operating parameters and the baseline media effectiveness rating, determining a media effectiveness model, based at least in part of the media effectiveness model, determining a loss in evaporative benefit cost over time, determining a time t when the loss in evaporative benefit cost exceeds the media replacement cost, and scheduling media replacement at time t.