10 ppm out of RO unit... ?!

[curiousphil]

Hey guys,

Just installed new RO membrane and filters on my unit for the second time, looking for some advice on a problem I'm having.  I've got the BRS 5 stage RO/DI unit and when I first got it I was reading 2-4 ppm out of the RO and into the DI.  The filters lasted until last October approximately, at which time I replaced everything except the RO membrane with filters from GoReef.  The sediment filter quickly fouled and my TDS readings out of the RO unit started to climb again.  The water at my new house is much more dirty than the old house, so I decided to go back to BRS and get the GE ROSave.Z Depth Sediment Filter which is supposed to have a much higher capacity than your standard 5 micron sediment filter.  And I figured if I am going to change one filter, I may as well change them all, and it's been a year so I decided to throw in a new RO membrane as well. 

Well, now I am getting 10 ppm out of my RO unit!!! 1-2 ppm after the DI.  Did not replace the DI resin yet and I don't really want to do so until I saw a good 1-2 ppm coming out of the RO side.  I've got the membrane flush kit on my unit and I flushed the system for a good 30+ minutes this weekend... no help.

Any thoughts of some things I should check??  Is it possible to install filters upside down?  I'm planning to rip the unit apart tonight and try to diagnose the problem but wanted to test the waters and see if there's any common errors I should keep my eye open for...

Thanks in advance.

 

[shipwreck]

Time for new membranes by the sound of it. They do have to be changed well. If chlorine or worse chloramine reach the membranes they will wreck them. Or if your pre filters pass to many solids damage can be done. Using your to system as the top off turning on/off for small amounts of water throughout the day can also cause problems.

 

[curiousphil]

Replaced my membrane as well this time around.... I'm quite confused

 

[shipwreck]

Chlorine/chloramine will destroy it very quickly. Do you use pre carbon filter?  Measure the TDS of the water pre RO. A membrane  will reduce the TDS by a factor only. So in a normal water supply your TDS will probably be around 100-200 which it can easily remove. If your water has real high TDS it may not be able to drop the output as far.

 

[curiousphil]

I'm using all new filters, this weekend I installed brand new:
-GE ROSave 5 micron sediment filter
-Matrikx 5 micron carbon block
-Matrikx 0.6 micron carbon block
-GE 100 gpd membrane

Holding off on installing the new DI resin until I bring the TDS out of my RO back into line.

Prior to that everything was the same except I was using a 5 micron Puritek sediment filter and I was getting 1-2 ppm after the RO.  From what I've read, London water doesn't have chloramines and the carbon filters should be sufficient for removing chlorine (and have been in the past).  So I'm thinking that I physically installed something incorrectly... like maybe a filter is upside down or something, if that is even possible.  I've never seen such high PPM out of my RO unit except when my filters were ready to change.

 

[Pistol]

Is your water treated with chloramine?, you might have to call the city to find out or google it, if it is then you need to run a GAC (granular activated carbon) as one of your prefilters to remove the chloramine.

 

[curiousphil]

No chloramine in London:
http://www.watersupply.london.ca/Quarterly_Reports/Archives/4Q2013/Q4_2013_Huron.pdf
http://www.watersupply.london.ca/Quarterly_Reports/Archives/4Q2013/Q4_2013_Elgin.pdf

And I've always had 1-2 PPM after RO until this week.

 

[Reef Hero]

Have you always run a 100gpd membrane?? Do you have an auto shut off switch installed on it? Perhaps it's your flow restrictor?? I have also read that a 100gpd membrane will always have a lower rejection rate than a 50 or 75.... I believe they are physically different. Another thought could be ur tds meter itself... Just throwing ideas out there....
Oh and what's ur water pressure at going into membrane

 

[curiousphil]

Yeah I've always used the 100 GPD.  Got it with the unit and changed it for the first time this weekend.  I don't have an auto shut off switch installed because I always run it manually.  Hook it up to the tap via an adapter, run it on flush mode for 5-10 mins, wait for the TDS out of the RO to come down , then turn off the flush and manually fill my FW container.

Not sure exactly what the water pressure going into the membrane is but it's over 80.  And yeah it does have a lower rejection rate than a 75 GPD - according to BRS the 100 GPD has a 96% rejection rate vs 98% on the 75.

Didn't think about the possibility of it being the TDS meter!  It was exposed to very high #s, in the hundreds, when I first started flushing the new membrane.

 

[Reef Hero]

I don't flush my membrane near as often as you do or for as long..... You do it every time?
I actually just installed a flush kit on mine a few months ago...... Never had one before..... Have you always flushed the membrane as often as you say you do now?


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[Duke]

I flush mine for like 2 minutes every 100 gallons or so, only cause it has the flush kit. My old Rodi never got flushed.