New RO membrane. High TDS. Don’t blame the membrane yet.

A newly installed RO membrane can still produce high-TDS permeate. Before blaming the membrane, check the most common causes: insufficient flushing to remove preservative, O-ring leakage or incorrect installation, contaminated permeate piping, uncalibrated conductivity meters, high feed-water TDS, and chlorine oxidation. In many cases, the membrane is fine — the problem is in the system around it. Follow a proper troubleshooting sequence: confirm rinse time, inspect O-rings and installation direction, test permeate TDS directly at the housing, calibrate instruments, and check feed water quality. Fixing these issues first can avoid unnecessary membrane replacement and restore stable performance.