RO Membranes - How do they work?

At the heart of every RO and RO/DI system is the RO Membrane. The Reverse Osmosis Membrane is also called a TFC (Thin Film Composite) Membrane.  

The RO Membrane works by using water pressure to separate impurities from purified water. The purified water passes through layers of semi-permeable membrane and is collected through the center channel. This very-thin membrane contains billions of very small pores. Water molecules are able to pass through these pores while contaminates are too large to pass through. The dirty/waste water is separated from the purified water and exits a separate port on your RO system.  

Typically, an RO membrane will remove approximately 95% of TDS (total dissolved solids) from the water. If your source water has a TDS of 100ppm (parts per million), the RO will reduce that TDS down to about 5. If your source water has a TDS of 500ppm, the RO will reduce the TDS down to about 25ppm.

The RO Membrane is very effective at purifying water. It can remove up to 99% percent of over 100 contaminates, such as: Calcium, Sodium, Magnesium, Potassium, Manganese, Iron, Aluminum, Copper, Nickel , Cadmium, Silver, Zinc, Mercury, Hardness Ca & Mg, Radioactivity, Chloride, Ammonium, Bromide, Phosphate, Chromate, Cyanide, Sulfate, Thiosulfate, Silicate, Silica, Nitrate , Boron, Borate, Fluoride, Polyphosphate, Orthophosphate, Chromate, Bacteria, Uranium, Arsenic, Lead. 

While being one of the best options for filtering dissolved solids, an RO membrane is not effective for removing organic compounds, bacterial microorganisms, chlorine by-products, dissolved gasses like carbon dioxide and methane. Pre filtration with sediment filters, carbon filters and post filtration with deionization filters and UV sterilizers helps to address these issues.  

As a clean membrane surface is necessary for the RO membrane to work efficiently, regularly flushing the membrane will help to prolong the life of the RO membrane and allow it to work efficiently. If your system does not have a flush kit, you can easily add one. When the membrane is flushed, water bypasses the flow restrictor. A strong stream of water flows along the surface of the membrane helping to flush away accumulated particulates.  

With its efficiency and its effectiveness, Reverse Osmosis filtration has become the most-popular option for aquarium hobbyists and for drinking water. AquaFX offers numerous RO and RO/DI systems and configurations to meet the needs of just about any application.