RO membranes. How long can they sit?

[Jonreefer]

So how long could a RO membrane sit before I couldnt use it anymore. I got it last summer and used it for maybe 150g before I took the tank down. Now I have new carbon, micron filter and such but could I still use the RO membrane or not..its been sitting for about 8months.

 

[stunreefer Verified Sponsor]

Have you kept it wet, or did it dry out?

 

[Jonreefer]

i am pretty sure it was still wet inside it..all the other canisters on the unit had water in them

 

[RBursek]

They recomend for storage to put it in a sealable bag with some RODI water and refrigerate if storing for more then 2 months. I would run it and check your TDS and see if the seem reasonable, the inlet to out let ratio. It should be between 96-98%, unless it is a 100gpd membrane they run 90%.

 

[AZDesertRat]

The only way to tell is with a TDS meter. Manufacturers recommend if they are not going to be used in 10-14 days place them in a zip loc bag with some DI and store them in the back of the refrigerator. Same ith DI resin.
Generally, once a membrane has been wetted and used it should never be allowed to dry out, the glues can delaminate and the membrane ruptures.

Test it with your TDS meter to determine if its working or not. You will need to test the tap water TDS, RO only TDS and RO/DI TDS (if you have RO/DI) to determine its condition. Depending on which membrane it is it should be 90-98% efficient, the higher the better. If its a Dow Filmtec 100 GPD only, it may be as low as 90% or less.

 

[Jonreefer]

i just ordered a new 75gpd from Bulkreefsupply

 

[AZDesertRat]

If you can stop the order it might pay off.
You can get a 90GPD batch tested and treated membrane from Spectrapure that will outperform the one you ordered for only $30 on sale right now.
Better and cheaper too, can't beat that!
SpectraPure Customer Appreciation SALE! 20% - 50% off

Spectrapure is the only company that wet tests and treats their membranes with a proprietary process then ships them wet in a vacuum sealed foil bag for freshness, others come off the shelf untested and dry. This process almost always results in better than 98% rejection or efficiency compared to about 97% for the average dry membrane based on 25 years of bench testing. These results are important not only in an RO only system but in a RO/DI an extra 2% rejection DOUBLES the life of your DI resin saving you even more money.
Spectrapure is also a Sponsor of this forum and has a Sponsors Forum here to answer all your questions.

 

[Jonreefer]

ill just go with the 75gpd BRS..I needed to get the 2 part dosing supplies off them. so it was a combination order