As your system ages it is natural that certain parts wear over time. The issue of low product water quality is typically an issue with a worn feed pump head, or that it is time to rebuild the Clark Pump. Low production is not typically a problem with the membranes on Spectra Watermakers. We recommend that you keep a log so that you can see that the feed pressure has dropped, or the salinity has increased. There are technical bulletins in the manual that will help you understand what is happening, and walk you through tests that can be performed to identify the cause of the low production.