I've had my Kent RO/DI unit up and running for about six weeks now. In that time I produced about 150 gallons of water. Now my production is almost zero. I'm getting one drop every 8 seconds with no waste water being produced. My pre filter is slightly discolored (rust colored), but the carbon and resin look fine. I'm going to get in touch with Kent on Tuesday, but I thought I could get better advice here. Thanks. Sorry Len