Filters4you 50 GPD RO Membrane for Under Sink Reverse Osmosis - 1 Pack

• 50 GPD THIN FILM COMPOSITE MEMBRANE - One polyamide TFC reverse osmosis membrane rated at 50 gallons per day, the standard 11.75 by 1.75 in element that fits most under sink RO systems. This is the stage that does the actual reverse osmosis and reduces total dissolved solids.
• MATCH THE RATING TO YOUR SYSTEM - 50 GPD is the lower production rate in this range and it suits most household systems. Higher ratings fill the tank faster but send more water to drain doing it, so check the number on the membrane you are removing rather than assuming higher is better. Gallons per day is production under ideal pressure and temperature, not what comes out of your tap; real output is lower and the storage tank covers the gap.
• FITS MOST STANDARD UNDER SINK RO SYSTEMS - The standard 1812 element used by APEC ROES-50, ROES-75, ROES-100, RO-90, RO-45; GE GXRM10RBL, GXRM10G, GXRV10; Olympia OROS-50, OROS-80; Watts WP-4V, WP-5, RO-TFM-4SV, RO-TFM-5SV, WPRL-58 and ZeroWaste; Krystal Pure KR10, KR15; plus HDLORF4, PNRV12, RO5MX, RCC100P, RCC7, F5-75, RFK-5, CMP10-F, Culligan 1000R, Simpure SP4-RO75, TGI-525, H5000 and HX-RO.
• CHANGE THE CARBON PREFILTERS ON TIME - Chlorine damages thin film composite material, so a spent carbon prefilter is not just a taste problem; it is passing chlorine straight to the membrane. Prefilters change every six months, the membrane every two to three years. Fitting a new membrane behind an old carbon block wastes it.
• HOW TO TELL WHEN IT IS SPENT - A rising TDS reading points at the membrane. Falling flow at the faucet usually points at the prefilters instead. A membrane is not a taste stage and not a softener; it does not change your water hardness. Compatible replacement membrane, not an original manufacturer part.

Filters4you 50 GPD reverse osmosis membrane, one per pack, a polyamide thin film composite element measuring 11.75 by 1.75 in that fits most under sink RO systems. The membrane is what separates a reverse osmosis system from an ordinary filter. Everything ahead of it is preparation: sediment holds back grit, carbon reduces chlorine, and then the membrane does the actual reverse osmosis under pressure, reducing total dissolved solids rather than straining particles out. Match the rating to the membrane you are replacing. At 50 GPD this is the lower production rate in the range and it suits most household systems; higher ratings fill the storage tank faster but send more water to drain doing it, so fitting a bigger membrane changes how much water you use as well as how quickly you can refill. Gallons per day describes production under ideal pressure and temperature rather than what comes out of your tap; real output is lower and the tank covers the difference between production rate and how fast you fill a glass. If a system seems slow, low incoming pressure is the usual cause rather than a failed membrane, and a pressure gauge will tell you more than a new membrane will. Changing the carbon prefilters on time is the single thing that decides how long this lasts. Chlorine damages thin film composite material, so a spent carbon block is not only a taste problem, it is passing chlorine straight to the most expensive part of the system. Prefilters change about every six months while the membrane normally runs two to three years, which means fitting a new membrane behind a tired carbon block wastes the new membrane. Telling which part is due is simple: a rising TDS reading points at the membrane, while falling flow at the faucet usually points at the prefilters. A membrane is not a taste stage and it is not a softener; it does not change your water hardness. This is a compatible replacement membrane and model numbers are used for reference only.