As with any rubber / silicone hose below waterline, the PSS Pro bellow must be inspected on a regular basis for any signs of wear, aging or chemical deterioration. PYI recommends that the bellow to be replaced once every 6 years.During the bellow replacement it is also recommended that the o-rings and set screws be replaced, as well as the hose clamps. PYI includes all the necessary replacement parts in the PSS Maintenance Kit.