RO membrane

[cccapt]

Can or will anything happen to an RO membrane if it's just taken out of the bag and let sit out? Someone I know picked up a new but not in any packaging, RO membrane. When they hooked it up, no water made it thru the membrane. It was 100% rejection.

[cccapt]

Anyone even use RO? ;)

[AZDesertRat]

Most RO membranes are shipped dry so as long as it had not been used beforehand it should work fine. The only exception is Spectrapure who treats their membranes with a proprietary process and keeps them wetted when shipped.
There is no such thing as a 100% rejection membrane, maybe 100 GPD?

[cccapt]

What I mean by 100% rejection rate is 100% of the water came out the waste line. NO water came out filtered thru the membrane.

[AZDesertRat]

Sounds like it is missing a flow restrictor. You should have a restrictor in the waste line to provide backpressure to force water through the membrane.
A quick way to see if this is true or not is to either temporarily install a ball valve on the waste line and close it or kink the end of the waste line andsee if water comes out the good line. Without a flow restrictor you probably won't get any good flow.

[cccapt]

Flow restrictor is in place. I also did try kinking the waste line to test it as you suggested. No water came out thru the membrane. The only thing that was changed on the filter was the membrane. The old membrane still works.

[AZDesertRat]

Try reseating the membrane all the way down in the housing, it may not be all the way in and is bypassing.

[Buckeye Hydro]

Good advice above from the rat man.

[cccapt]

Yes, good advise, but I still don't have an answer. I've been using RO/DI on my tank for 20 yrs. I know how to install a membrane.
Can an RO membrane dry out or what would cause it not to allow water to pass thru it?

[AZDesertRat]

If its bypassing its taking the path of least resistance and not going through the membrane. You asked for advice and we provided it. Non seated membranes are common no matter how long you have been doing it or how smart you think you are.

[cccapt]

Non seated membranes are common no matter how long you have been doing it or how smart you think you are.
thanks....lol

[AZDesertRat]

I am not ashamed to admit I have had this problem a well as hooking up autoshutoff valves wrong or installing check valves backwards, we all have bad days sometimes:D

[Buckeye Hydro]

Assuming the membrane has never ben wetted, there is no "drying out" that could occur. I suspect:
you are missing the flow restrictor
the membrane isn't seated
you have a flush valve in the "open" position
the pressure in your system is too low to drive water through the membrane due to badly clogged prefilters or plain old low line pressure.

Russ

[rocknreef]

I would have to agree with all the above.

I would try putting a different RO membrane in it and see what happens. New or old membrane just to see if water flows or not.

My first thought was the filter should be fine if it was never used even if it was not in the package. But if it was not in the package how to you know it was never wet. Thus now dried up and not allowing water to flow.

[cccapt]

As I mentioned above, I did reinsert the old membrane and that did work. I also put the "new one" in a few times with the same result. No water thru the membrane.
I don't know if it was used previously and got wet.

[Buckeye Hydro]

That may be the answer. If it was wetted and then dried it is ruined (I expect you would at least get a little water through it however).