Do I need to replace my RO membrane?

[saltyhog]

My RO/DI system is 6 years old and my membrane is the original one.

My TDS from the tap is 35-43 and for the past 6 years the TDS after the RO has been 0-1 (usually 0). In the last few weeks however, it's risen to 2ppm pretty regularly. Is it time to replace it?

Is there an expiration date on membranes? I have a replacement that I bought 4 years ago but didn't use because it wasn't needed. Its still sealed in its original plastic bag.

 

[Potatohead]

If you have it already on hand I would probably replace it. 2 ppm vs 1 ppm sounds like nothing but it means you will go through DI resin twice as fast. As long as your spare one has not been wet and dried out, it's fine.

 

[DesertReefT4r]

You did really well getting that long out of a membrane. I would replace it personally just due to age but 2 ppm is still 97% rejection or better. That is still a good membrane so its up to you honestly.