Membrane Cleaning

On rare occasions, a membrane can suffer from organic buildup. In this situation, the TDS may be acceptable, but the flow rate decreases. It should be noted that in most cases, a reduced flow rate is due to a restriction in the system, clogged prefilter, or worn impeller. Cleaning the membrane should only be considered after exhausting other flow rate issues.

Instructions for cleaning membranes:

  1. Flush your Rainman with 10 litres (2.5 gallons) of fresh unchlorinated water as per your operations manual. Ensure system is unpressurised (pressure control valve fully open) when flushing water through.
  2. Prepare 20 litres of cleaning solution by mixing 400 grams (1 lb) of powdered alkaline membrane cleaner and desalinated product water (or other unchlorinated fresh water). If the solution is purchased from Rainman, use half the tub.
  3. Put the intake hose and brine waste water hose into the bucket.
  4. Divert the product water hose away from your tanks to waste.
  5. Run the system unpressurised (pressure control valve fully open) for ten minutes.
  6. Turn system off and leave for 12-24 hours.
  7. Reconfigure the hoses to normal operation and run the system for 10 minutes to fully flush the mix.