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Membrane Life

Posted: Wed Mar 22, 2006 10:25 pm
by snoopdog
I know the manufacturers of the membranes suggest 1 year for a change out time frame but how far can you stretch these things. From what I have heard before they still only put out zero tds at the end of there life, just slower right ? I have a resevoir so speed of water is not an issue for me, since I get about 5 gallons per batch without wait so when do I really have to change them ? I try to change the carbon and pre filters about 6-12 months so far.

Posted: Thu Mar 23, 2006 7:16 am
by Brandon
I'm curious on this one too.

Posted: Thu Mar 23, 2006 7:18 am
by 99lsfm2
Do you flush your membrane every week or so?
http://www.kentmarine.com/instructions/flushkit2.pdf

Mark

Posted: Thu Mar 23, 2006 7:40 am
by Amphiprion
Unfortunately, the actual useful life can vary dramatically. It depends upon what all is in your water, if you take care of the membrane (i.e. don't let it dry, get exposed to chlorine) etc. Besides ridding the membrane of larger particles, flushing does nothing to extend membrane life.

Posted: Thu Mar 23, 2006 8:43 am
by snoopdog
I always thought the "flush the membrane" the most unrealistic thing I ever heard of. Ok once a week, that is 52 times a year. I am sorry I will buy a membrane once a year before I subject myself to that. I am lucky to get my water changed 4 times a year as it is.

From what I understand the people that make R.O. Water, like B&B squeeze every drop out of there membrane before they change it. This is the point when the outlet just drips and no longer has a steady stream. I am thinking of just relying on my TDS meter to tell me when the TDS starts getting high. I am due for a cartridge change now as it is, maybe this weekend. Compared to the old house I notice the cord filters are a nicer white and the old house they would get a nice orange, nice huh ?

Posted: Thu Mar 23, 2006 9:20 am
by Amphiprion
Yes, using a TDS meter is probably the BEST way to guage the membranes efficacy and longevity, rather than relying on biased manufacturer recommendations.

Posted: Thu Mar 23, 2006 4:26 pm
by mykpoz
anyone have a good link of connecting a resevoir to an ro/di system?

my ro/di unit didnt come with one, but i think i'd like to add one, and I am curious as to the various possibilities out there to acomplish this. etc.

thanks

Posted: Mon Dec 11, 2006 4:00 am
by Buckeye Field Supply
Folks you should be getting much more than a year from an RO membrane, assuming you have adequate prefilters and change them on schedule. We have a customer that has had the same membrane for 7 years. 2-3 years is more typical.

The two signs of a membrane gone bad are reduced rejection (higher tds output) and reduced production (fewer gpd).

Russ @ BFS

Posted: Mon Dec 11, 2006 4:00 am
by Buckeye Field Supply
mykpoz wrote:anyone have a good link of connecting a resevoir to an ro/di system?

my ro/di unit didnt come with one, but i think i'd like to add one, and I am curious as to the various possibilities out there to acomplish this. etc.

thanks
Are you talking about adding a pressurized storage tank?

Posted: Mon Dec 11, 2006 10:58 am
by mykpoz
at the time, I was.

I am also in my +1 year life on my current filter tested at 0 on 2 different TDS meters.

go go filter!

Posted: Mon Dec 11, 2006 7:09 pm
by Buckeye Field Supply
Adding a tank is pretty straightforward. You'd end up with a sytem plumbed something like this system:

Wondering

Posted: Tue Dec 12, 2006 1:18 am
by SadaAesix
I was wondering, I know that optimally you want a tds reading of 0.0 ppm but I have a reading of 0.10 ppm.
I also have a problem with a high ammonia reading from the output water. I am going to change the chamber filters out but should I change the membrane out as well?

Membrane life

Posted: Tue Dec 12, 2006 1:22 am
by SadaAesix
I recently spoke to a corallife tech about my ammonia problem and he told me that usually membranes are good for 2-3 years if properly maintained and flushed.

Posted: Tue Dec 12, 2006 3:25 am
by Buckeye Field Supply
I think what you have is 10 ppm rather than 0.1 ppm, correct? If ammonia is making its way through, your resin is likely shot. Do you have chlormaine in your water?