We have had ours now for over 2 years and love it. It works well and NO filter is ever needed. More products should be like this. Just note, if you use this in a bedroom, make sure you are not using full mist otherwise you can cause too much moisture and possible mold growth on your bedroom wall. So far so good with this unit. We only use distilled water and never had any issues. When you first start it up after it sits, it may take awhile before you see mist. We prefer this model since it does not use any filter and no chemicals are needed to treat the water. Great product. The reservoir and bottom can be rinsed before you store it away for the summer. Make sure you let it air dry before packing it back up again.