Coralife Pure Flo II Reverse Osmosis TFC MembranePure Flo II R/O TFC Membrane is part of the Coralife Pure Flo II Reverse Osmosis System. The key component for any R/O unit is its membrane. The membrane will determine the type of contaminants removed and how much water the unit will produce. Coralife's Pure Flo TFC (Thin Film Composite) membranes will remove up to 98% of nitrates, up to 95% of silicates and is excellent for TDS (Total Dissolved Solids) removal. Coralife Pure Flo II Reverse Osmosis Membrane Removal Rates: Aluminum 96%-98%, Lead 95%-98%Ammonium 80%-90%, Mercury 94%-98%Bromide 90%-95%, Nickel 96%-98%Cadmium 93%-97%, Nitrate 96%-98%Chromium 95%-97%, Phosphate 95%-98%Copper 96%-98%, Silicate 96%-95%Hardness 93%-97%, Sulfate 96%-98%Iron 96%-98%, Zinc 96%-98%Maintenance/Lifespan: Should last a minimum of 1 year if used and stored properly. The membrane should always be used with micron pre-filter and with carbon pre-filter (if used with chlorinated water). Can be stored wet inside R/O canister for up to 30 days (should never be stored dry). If more than 30 days between use, can be stored in refrigerator (cannot be frozen) along with a small amount of purified water in a sealable bag. The lifespan and effectiveness of these membranes can also be increased by back flushing these canisters following the instructions provided within the units.