Time to replace TFC on R/O unit?

10" Red Devil · 05/15/2006, 03:14 PM

Hello,

I am wondering if the reason I have a sputtering noisy waste line (red) all of a sudden after a year and a half of use if its time to replace the TFC? My tds reads 2 and the salifert Po4 kit does not register any po4 comming out of the unit. Or is this a sign of something else? This is just a Bare Bones R/O unit with a GAC chamber and a TFC membrane chamber. Our Tap has pretty low TDS.

The unit is still producing r/o water, but it is so rediculously noisy from the red line bouncing around that I need to fix this.

Thanks for any suggestions.

10" Red Devil · 05/15/2006, 03:42 PM

bump

AZDesertRat · 05/15/2006, 05:41 PM

If you have never replaced the carbon since you have had the unit there is a possibility you have damaged the RO membrane(what you are calling TFC) due to chlorine eating the thin film composite RO membrane fabric. Carbon should be replaced at least every 6 months and maybe more often if you only have one carbon filter and its just GAC and not a carbon block. If you can test for chlorine after the RO, if you see any its probably time for a new membrane.

10" Red Devil · 05/15/2006, 06:30 PM

I replaced the GAC once. I did not know you had to change the GAC as often but I guess it is supposed to be ever 300 gallons which im pretty sure I well surpased. Is there really that much chlorine in our water that could do that to the membrane?

I will have to pick up a chlorine test.

Thanks for you help!

AZDesertRat · 05/15/2006, 06:43 PM

You probably have anywhere from 0.5 to 2.0 ppm chlorine residual in municipal drinking water. GAC will not adsorb as much chlorine as a good carbon block like a "Chlorine Guzzler". Some good carbon blocks are rated for up to 20,000 gallons of normal chlorinated water. Since you don't have a prefilter I would use a 0.6 or 1 micron size carbon block instead of the GAC so it helps protect the RO membrane from suspended solids.

10" Red Devil · 05/15/2006, 08:25 PM

I was told by the local fish store guy that the membrane that I use is to remove chlorine. Of course you are a water/wastewater operations consultant for a living so of course Im going to listen to what you have to say over the local fish store owner, but is this possible? Are there TFCs that remove chlorine?

Thanks.

10" Red Devil · 05/15/2006, 08:26 PM

Oh and where can one get those 0.6 to 1 micron size carbon blocks?

Thanks.

AZDesertRat · 05/15/2006, 08:50 PM

Chlorine will destroy a TFC RO membrane, thats why it is very important to have a good carbon filter before the membrane. Some better quality units even have two carbons before the membrane plus a prefilter.
I would look at one of these four places. All sell only the best components and have great customer service.
www.purelyh2o.com
www.airwaterice.com
www.buckeyefieldsupply.com
www.thefilterguys.biz
You will find a new high quality unit is not a whole heck of a lot more than a replacement membrane and carbon filter, plus it will get you a DI filter also which gets you down to 0 TDS.

10" Red Devil · 05/17/2006, 10:52 AM

AZDesertRate,

Since you are so knowledgeable about this stuff which btw thanks for your help! I was wondering if they have something that is not too expensive that lets you know when your GACs (or in the future when I upgrade to the 1 micron/r/o filter from say purelyh20.com like you suggest) is spent. I know you are supposed to replace the regular GACs every 300gallons. I mean short of keeping a log which can get annoying in this fast paced life. Plus I have more then a few times Fd up and left the water running went away for a day and came back and forgot that I had left it on (fortunately if it overfills the container it just goes down a wash basin).

AZDesertRat · 05/17/2006, 11:55 AM

Most vendors recommend replacing the pre filter and carbons every six months. I like this method so I don't have to keep track of how many gallons I have produced, I just put a mark on the calendar so I remember to change them.

10" Red Devil · 05/17/2006, 12:21 PM

Great Idea,

Thanks AZ! Will put that to use!

05/15/2006, 03:14 PM	#1
10" Red Devil Registered Member Join Date: Jun 2005 Location: Michigan Posts: 1,611	Time to replace TFC on R/O unit? Hello, I am wondering if the reason I have a sputtering noisy waste line (red) all of a sudden after a year and a half of use if its time to replace the TFC? My tds reads 2 and the salifert Po4 kit does not register any po4 comming out of the unit. Or is this a sign of something else? This is just a Bare Bones R/O unit with a GAC chamber and a TFC membrane chamber. Our Tap has pretty low TDS. The unit is still producing r/o water, but it is so rediculously noisy from the red line bouncing around that I need to fix this. Thanks for any suggestions.

05/15/2006, 03:42 PM	#2
10" Red Devil Registered Member Join Date: Jun 2005 Location: Michigan Posts: 1,611	bump

05/15/2006, 05:41 PM	#3
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	If you have never replaced the carbon since you have had the unit there is a possibility you have damaged the RO membrane(what you are calling TFC) due to chlorine eating the thin film composite RO membrane fabric. Carbon should be replaced at least every 6 months and maybe more often if you only have one carbon filter and its just GAC and not a carbon block. If you can test for chlorine after the RO, if you see any its probably time for a new membrane.

05/15/2006, 06:30 PM	#4
10" Red Devil Registered Member Join Date: Jun 2005 Location: Michigan Posts: 1,611	I replaced the GAC once. I did not know you had to change the GAC as often but I guess it is supposed to be ever 300 gallons which im pretty sure I well surpased. Is there really that much chlorine in our water that could do that to the membrane? I will have to pick up a chlorine test. Thanks for you help!

05/15/2006, 06:43 PM	#5
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	You probably have anywhere from 0.5 to 2.0 ppm chlorine residual in municipal drinking water. GAC will not adsorb as much chlorine as a good carbon block like a "Chlorine Guzzler". Some good carbon blocks are rated for up to 20,000 gallons of normal chlorinated water. Since you don't have a prefilter I would use a 0.6 or 1 micron size carbon block instead of the GAC so it helps protect the RO membrane from suspended solids.

05/15/2006, 08:25 PM	#6
10" Red Devil Registered Member Join Date: Jun 2005 Location: Michigan Posts: 1,611	I was told by the local fish store guy that the membrane that I use is to remove chlorine. Of course you are a water/wastewater operations consultant for a living so of course Im going to listen to what you have to say over the local fish store owner, but is this possible? Are there TFCs that remove chlorine? Thanks.

05/15/2006, 08:26 PM	#7
10" Red Devil Registered Member Join Date: Jun 2005 Location: Michigan Posts: 1,611	Oh and where can one get those 0.6 to 1 micron size carbon blocks? Thanks.

05/15/2006, 08:50 PM	#8
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Chlorine will destroy a TFC RO membrane, thats why it is very important to have a good carbon filter before the membrane. Some better quality units even have two carbons before the membrane plus a prefilter. I would look at one of these four places. All sell only the best components and have great customer service. www.purelyh2o.com www.airwaterice.com www.buckeyefieldsupply.com www.thefilterguys.biz You will find a new high quality unit is not a whole heck of a lot more than a replacement membrane and carbon filter, plus it will get you a DI filter also which gets you down to 0 TDS.

05/17/2006, 10:52 AM	#9
10" Red Devil Registered Member Join Date: Jun 2005 Location: Michigan Posts: 1,611	AZDesertRate, Since you are so knowledgeable about this stuff which btw thanks for your help! I was wondering if they have something that is not too expensive that lets you know when your GACs (or in the future when I upgrade to the 1 micron/r/o filter from say purelyh20.com like you suggest) is spent. I know you are supposed to replace the regular GACs every 300gallons. I mean short of keeping a log which can get annoying in this fast paced life. Plus I have more then a few times Fd up and left the water running went away for a day and came back and forgot that I had left it on (fortunately if it overfills the container it just goes down a wash basin).

05/17/2006, 11:55 AM	#10
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Most vendors recommend replacing the pre filter and carbons every six months. I like this method so I don't have to keep track of how many gallons I have produced, I just put a mark on the calendar so I remember to change them.

05/17/2006, 12:21 PM	#11
10" Red Devil Registered Member Join Date: Jun 2005 Location: Michigan Posts: 1,611	Great Idea, Thanks AZ! Will put that to use!