I use it a cple of times a day along with brushing and flossing. The last wp 100 was good for a long time. I keep good care of it too following care instructions.
Been enjoying our waterpik for a few weeks and I like it so much better than flossing. Gets between most of my teeth, cleans gum line, mouth feels good. I still floss between a couple tight teeth. I also have to be careful about spraying but just takes a little practice.