Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not a good purchase

We purchased two of these about 1.5 years ago. One unit failed within 6 months. The other is still working but not very well. You have to turn it on and off several times to get the water to flow. It works for my husband but I have to then bang it on the counter to get it to work. We empty it every use but it still grows mildew under the top cover and under the well. We just received the new Phillips Airflosser - hopefully it will be better. I wouldn't recommend the Waterpik unit.