High TDS after replacing all filters and membrane

Spiderman097 · 12/15/2019, 11:15 AM

Hi,I replaced all my filters the other day.

I've let the RODI unit run for the past 48 hours and the TDS after the RO membrane is still high 35 tds.I've verified with another*inline TDS meter, and I've taken the RO membrane apart and reseated. I'm not sure what the issue could be.

TDS before membrane 45 tds
TDS after membrane 35 tds
Pressure 70 psi

mcgyvr · 12/15/2019, 11:22 AM

Do you have a DI stage?

Have you tried to reseat the membrane?
Did you install the membrane the right way?

Its clearly not seated/installed correctly or faulty

Spiderman097 · 12/15/2019, 11:52 AM

The DI stage is after the membrane and is not connected at the moment due to the high TDS. I did take the membrane out and reseat it. According to the BRS video, the 2 rubber gaskets on the bottom. I bought 2 RO membranes and they are both testing exactly the same.

I thought it was the tds meter at first, so I pulled another in-line tds meter off another RO unit and the exact same readings.

heritage · 12/15/2019, 12:00 PM

So this is a new membrane?
If so then I would think that the membrane is bad.
Have you checked the waste water ratio ?

Spiderman097 · 12/16/2019, 01:39 PM

Checking the water ratio now.

mcgyvr · 12/16/2019, 02:13 PM

Quote:

Originally Posted by Spiderman097

The DI stage is after the membrane and is not connected at the moment due to the high TDS. I did take the membrane out and reseat it. According to the BRS video, the 2 rubber gaskets on the bottom. I bought 2 RO membranes and they are both testing exactly the same.

I thought it was the tds meter at first, so I pulled another in-line tds meter off another RO unit and the exact same readings.

Unlikely that 2 membranes are bad.. but possible I guess..

And yes the 2 rubber orings on the one end go in first and the larger black ring (brine seal) should be near the cap..
You need to use some force sometimes for that last 1/4" of travel to fully seat the membrane orings.

If your water is coming out of the RO membrane filter output too fast thats a good indication its not seated/installed properly.. Checking to see if you are achieving the proper gallons per day is a good check there

Spiderman097 · 12/16/2019, 06:55 PM

Did the water test, and the output of both waste and post membrane was expected. However, after thinking about it, I traced the good line to the in-line tds meter,and the only thing I could think of was the auto shutoff valve. I took the good lines out and ran it directly to the tds meter. 0 tds, and then the autoshut off valve started leaking because the RO lines were not in it; only the pre-membrane lines, so that tells me there was probably a hole in the shutoff valve, causing both pre and post membrane to mix.

Herndog · 01/09/2020, 08:29 PM

I need to see if bypassing the auto shutoff brings my post membrane TDS down. I have two membrane housings and the membrane bottoms out in both pretty easy - no need to push with palm for last quarter inch-harder to get out.

horsefarm5 · 01/19/2020, 05:50 PM

just happened to me me the other day . Make sure cartridge'sare facing the right way

12/15/2019, 11:15 AM	#1
Spiderman097 Registered Member Join Date: May 2011 Posts: 115	High TDS after replacing all filters and membrane Hi,I replaced all my filters the other day. I've let the RODI unit run for the past 48 hours and the TDS after the RO membrane is still high 35 tds.I've verified with another*inline TDS meter, and I've taken the RO membrane apart and reseated. I'm not sure what the issue could be. TDS before membrane 45 tds TDS after membrane 35 tds Pressure 70 psi

12/15/2019, 11:22 AM	#2
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Do you have a DI stage? Have you tried to reseat the membrane? Did you install the membrane the right way? Its clearly not seated/installed correctly or faulty __________________ Who me?

12/15/2019, 11:52 AM	#3
Spiderman097 Registered Member Join Date: May 2011 Posts: 115	The DI stage is after the membrane and is not connected at the moment due to the high TDS. I did take the membrane out and reseat it. According to the BRS video, the 2 rubber gaskets on the bottom. I bought 2 RO membranes and they are both testing exactly the same. I thought it was the tds meter at first, so I pulled another in-line tds meter off another RO unit and the exact same readings. Last edited by Spiderman097; 12/15/2019 at 11:53 AM. Reason: Wording

01/09/2020, 08:29 PM	#8
Herndog Registered Member Join Date: Oct 2006 Location: Missouri Posts: 63	I need to see if bypassing the auto shutoff brings my post membrane TDS down. I have two membrane housings and the membrane bottoms out in both pretty easy - no need to push with palm for last quarter inch-harder to get out. __________________ He Who? Who He? Current Tank Info: Reefer 250 / MP40QWD / Gen 5 Radion Pro / Apex / Trident

12/15/2019, 12:00 PM	#4
heritage Registered Member Join Date: Jul 2011 Location: PHILLY Posts: 561	So this is a new membrane? If so then I would think that the membrane is bad. Have you checked the waste water ratio ?

12/16/2019, 01:39 PM	#5
Spiderman097 Registered Member Join Date: May 2011 Posts: 115	Checking the water ratio now.

12/16/2019, 06:55 PM	#7
Spiderman097 Registered Member Join Date: May 2011 Posts: 115	Did the water test, and the output of both waste and post membrane was expected. However, after thinking about it, I traced the good line to the in-line tds meter,and the only thing I could think of was the auto shutoff valve. I took the good lines out and ran it directly to the tds meter. 0 tds, and then the autoshut off valve started leaking because the RO lines were not in it; only the pre-membrane lines, so that tells me there was probably a hole in the shutoff valve, causing both pre and post membrane to mix.

01/19/2020, 05:50 PM	#9
horsefarm5 Registered Member Join Date: Jul 2008 Location: New Jersey Posts: 176	just happened to me me the other day . Make sure cartridge'sare facing the right way