If you have a hot tub in your backyard, you need a hot tub filter to make it operate correctly. Some hot tubs won’t function at all without a filter in place, but even if yours will, do yourself and your family a favor and be sure to keep a filter installed in your hot tub at all times. These filters are usually made of paper or fabric, but they may also be made of ceramic or contain activated carbon media. The type of hot tub filter you choose depends on the type of hot tub you have. Your instruction manual should tell you the right type of filter for your hot tub.