If it's like the one I had at my house for our well water they do work well. However, they were really hard to do maintenance work on. You'd have a ringed "wrachet" to undo the a big cylinder. It was extremely difficult to undo. My ex-husband is a big man, 6'5" and he had to really mess with it. I think you're supposed to change the filters every 6 months if I remember right. Of course the bulbs are expensive. It was either every year or every two years you were supposed to replace. We bought them at a plumbing supply store.