roduct Water TDS Still High After Treatment — Your 4040 RO Membrane Is Telling You Something
If your RO system is running but product water TDS remains consistently high, the 4040 RO membrane is almost certainly the cause. A properly functioning membrane delivers 98 to 99 percent salt rejection. When rejection drops below 95 percent, water quality becomes unreliable and in regulated industries like pharma and food processing, this creates serious compliance risks. This resource explains the direct connection between membrane condition and TDS performance and what steps to take immediately when rejection rates decline.