Your Microfilter should be rinsed once a week. Depending on how often you use your hot tub, and how many people are using it, you may want to rinse more often. If you are enjoying your hot tub more than three times a week, you can rinse twice a week. If you are using Beachcomber’s Care Free water care program, be sure to rinse your Microfilter one per week. Your Microfilter should last from two to four years. We recommend having a spare, so that when one is in use, the other can be available for replacement and/or cleaning.