How to Clean a Residential Reverse Osmosis Membrane

Reverse osmosis is a mechanical means of filtration that reduces or eliminates particulate matter and helps to purify water. The process involves running water through a semipermeable membrane with tiny holes that are only a fraction of a micron in diameter. Home systems are housed inside plastic cylinders attached to the main water line. They are often used in conjunction with other filtration devices. Common types of household membranes are thin film and cellulose triacetate. Cleaning involves soaking in various chemicals followed by thorough rinsing to purge the membrane pores of impurities. You need to know what type membrane your system uses in order to get the right cleaning supplies.

Step 1

Shut off the valve to the water supply nearest the source of the filtration system. Disconnect the cylindrical housing that encases the reverse osmosis membrane from the filtration system and open the gasket to remove the membrane. Pull the membrane out and set it aside on a clean surface.

Step 2

Get only specifically designed products to clean cellulose or thin film membranes. For cellulose membranes, use a cellulose acetate membrane cleaner to remove organic matter and mineral scale. For thin film membranes use specially designed silica and silicates products that just remove silica. Mineral scale can be cleaned with an acid cleaner. Use an alkaline cleaner to help eliminate organic matter, oil, grime and grease within thin film membranes. Biofoulants such as mildew and mold can be removed using an anionic surfactant cleaner. Use one or all products depending on the quality of your water.

Step 3

Prepare a cleansing bath for the membrane. Don protective gear such as eye protection and rubber gloves and fill the plastic tub with water per chemical package directions. Soak the membrane for about one hour or use the manufacturer's recommended times. Remove and rinse with clear water at completion.

Step 4

Use disinfectants regularly to prevent bacterial colonies from propagating out of control, especially during warm or prolonged wet seasons, or if your water supply is not pretreated with chlorine or UV light. Read package directions for the recommended product mixing and for correct soaking times for your type of membrane.

Step 5

Replace the membrane into the housing and reattach it to the water line or system. Turn the water supply back on and run water through it for 15 to 30 minutes to flush it out.