In our RO Troubleshooting Series, we discussed that one of the causes may be dirty, scaled, or fouled membranes. Membranes do need to be routinely cleaned from time to time. Most of the major membrane manufacturers agree on the following statements:
1.) Reverse Osmosis membranes should be cleaned when normalized flow decreases by 10% from the initial acceptance test conditions
2.) Reverse Osmosis membranes should be cleaned when the overall pressure drop increases by 15% over the initial acceptance test conditions.
To know when your membranes need to be cleaned its good to have the start-up data. When you change your membranes you should use the “Start-Up” log (Click here for a copy of the Start-Up Log). Once you have this data you should be logging daily water quality, pressures, and flows to help determine when you are needing a cleaning. (Click here for a copy of the Daily Log.)
Cleaning membranes can be costly if not done correctly. While many RO Manufactures & Membrane Manufacturers have a cleaning process, you may want to verify that cleaning process with a water analysis. Some times cleanings need to be altered or changed based on water quality feeding the RO system. Cleaning RO membranes the wrong way can cause irreversible damage costing thousands of dollars in lost membranes!
Complete Water Solutions offers cleaning procedure reviews, chemicals, training, onsite cleaning services, and offsite cleaning services.