I've had my WP25 for three days love it so far. Very powerful and can easily create a nice standing wave. I like the option labeled as "else" it simulates a somewhat "random" pattern consisting of high flow and low flow as well as pulsing at differing intensities. That immediately kicked up all sorts of detritus. I don't have the night sensor and don't intend to. It's extremely quiet and cannot hear it at all. I hope it stands the test of time.