mling June 3, 2009 Share June 3, 2009 What is an acceptable reading for TDS ? I have had basic a air water & Ice RO/DI unit, with no TDS, for about 5 year before I decided to upgrade to a Typhoon III Extreme. For the last 5 years, I would only change my filters as recommended, yearly or 3 years for the membrane and all was well. I did not even know what TDS was; sometimes, no information is better . I hooked up my TyphoonIII on May 2nd. The TDS Link to comment Share on other sites More sharing options...
Neilan June 3, 2009 Share June 3, 2009 Obviously 0 is what you want. I just got my unit less than a year ago. THe first month I was encountering the same issue it sounds like you were. TDS all over the place, and my flow rate was super slow it seemed. I went ahead and replaced the Membrane and that solved my problem, so I just had a faulty membrane, even though it was sealed in the bag when I got it. Link to comment Share on other sites More sharing options...
mling June 3, 2009 Author Share June 3, 2009 Are there different brands of membrane ? Are they all the same or are there "band names" ? I would rather pay more than to have to change some cheaper ones more often. Link to comment Share on other sites More sharing options...
YBeNormal June 3, 2009 Share June 3, 2009 It is normal to have slightly elevated TDS when you first open the product valve, but 50+ is not normal at all. Is your Typhoon brand new? If so, contact AWI for assistance. It sounds like you might have a defective RO membrane. Link to comment Share on other sites More sharing options...
Coral Hind June 3, 2009 Share June 3, 2009 The membrane may not be seated properly in the pressure vessel. Also make sure there is no air trapped in the pressure vessel. Holding the vessel with the outlets up, tap it with something to dislodge the bubbles. I hit mine against the wall a few times. Link to comment Share on other sites More sharing options...
L8 2 RISE June 3, 2009 Share June 3, 2009 You want 0, and it should definetly not be higher than 5 if you're already going to be using an RO/DI Link to comment Share on other sites More sharing options...
mling June 3, 2009 Author Share June 3, 2009 It is normal to have slightly elevated TDS when you first open the product valve, but 50+ is not normal at all. Is your Typhoon brand new? If so, contact AWI for assistance. It sounds like you might have a defective RO membrane. I got it with the group buy you organized last year but only had time to hook it up early last month. The thing that confuses me is that it was working great for at least 2 weeks, 0 TDS. Then it went crazy this past weekend. While it may be that my RO membrane is bad, I still wonder if it is just coincidence that it happened the same time Fairfax Water Auth send that note saying they are flushing the water supply. Anyone else in Fairfax County notice such changes during this time frame ? I know we get our water supply from Bull Run (i.e. different source than DC, etc) Link to comment Share on other sites More sharing options...
m3fan8ic June 3, 2009 Share June 3, 2009 I have a same system I'll let you know what it reads when I get home this evening. Mine read aroud 1 or 2ppm few weeks ago when I checked; but my filters are few months old also. Link to comment Share on other sites More sharing options...
Origami June 3, 2009 Share June 3, 2009 I'm in Eastern Loudoun but we use Fairfax Water. Fairfax Water has two treatment plants: On e in Herndon and one in Occoquan. I'm served by water being processed in Herndon but don't know where your water comes from. I've not noticed a decrease in the performance of my AWI RO/DI system. I'd give them a call and ask their opinion on what's going on. It sounds to me like you may have a membrane failure or rupture. Link to comment Share on other sites More sharing options...
tygger June 3, 2009 Share June 3, 2009 I got it with the group buy you organized last year but only had time to hook it up early last month. The thing that confuses me is that it was working great for at least 2 weeks, 0 TDS. Then it went crazy this past weekend. While it may be that my RO membrane is bad, I still wonder if it is just coincidence that it happened the same time Fairfax Water Auth send that note saying they are flushing the water supply. Anyone else in Fairfax County notice such changes during this time frame ? I know we get our water supply from Bull Run (i.e. different source than DC, etc) I got a 75g membrane from that same group buy that i just installed a week ago (along with the prefilters). My TDS is at 8 without the DI. I cant recall the tap TDS reading right now... but I'll try flushing the membrane to see what happens. Link to comment Share on other sites More sharing options...
mling June 3, 2009 Author Share June 3, 2009 I'm in Eastern Loudoun but we use Fairfax Water. Fairfax Water has two treatment plants: On e in Herndon and one in Occoquan. I'm served by water being processed in Herndon but don't know where your water comes from. I've not noticed a decrease in the performance of my AWI RO/DI system. I'd give them a call and ask their opinion on what's going on. It sounds to me like you may have a membrane failure or rupture. I believe mine comes from Occoquan. I think it is the membrane. I also bought a "under the sink" RO drinking water and that is in the 30 to 40 ppm range. I assume that is the "ok" level for RO water. Link to comment Share on other sites More sharing options...
Coral Hind June 3, 2009 Share June 3, 2009 I believe mine comes from Occoquan. I think it is the membrane. I also bought a "under the sink" RO drinking water and that is in the 30 to 40 ppm range. I assume that is the "ok" level for RO water. 30 to 40 is still high! It should be less then 10. The RO membrane should reduce your tap by 90-98%. What is the tap TDS reading? Link to comment Share on other sites More sharing options...
Origami June 3, 2009 Share June 3, 2009 I believe mine comes from Occoquan. I think it is the membrane. I also bought a "under the sink" RO drinking water and that is in the 30 to 40 ppm range. I assume that is the "ok" level for RO water. Mine normally runs 0 ppm. When it gets to 4 or 5 (if not before), I begin to think about changing things. I take two measurements: One of the RO water out of the membrane and one out of the DI stage (RO/DI water). When the RO/DI creeps up, it's time to change the DI resin. When the RO numbers creep up, it's time to change the membrane. If the membrane's not doing it's job, you'll find that your DI resin will be depleted faster. Link to comment Share on other sites More sharing options...
mling June 4, 2009 Author Share June 4, 2009 30 to 40 is still high! It should be less then 10. The RO membrane should reduce your tap by 90-98%. What is the tap TDS reading? Tap TDS today is 140. The 30 to 40 reading for my other setup under the sink is taken using the hand held TDS reader that came with the Typhoon so I don't know if it is as accurate. Maybe it is like using a swing arm hydrometer versus a refractometer. Link to comment Share on other sites More sharing options...
blaze98 June 4, 2009 Share June 4, 2009 what are you using to hold the water while you are testing? If you use a regular cup or bowl you may be picking up other things like detergent residue. Link to comment Share on other sites More sharing options...
mling June 4, 2009 Author Share June 4, 2009 what are you using to hold the water while you are testing? If you use a regular cup or bowl you may be picking up other things like detergent residue. It was a regular cup. Would not a well rinsed cup be just a good ? Link to comment Share on other sites More sharing options...
blaze98 June 4, 2009 Share June 4, 2009 try a new disposable paper or plastic cup Link to comment Share on other sites More sharing options...
L8 2 RISE June 4, 2009 Share June 4, 2009 What I do when testing is get a small cup big enough for the tip of the TDS meter, rinse it out 2-3 times with the ALREADY FILTERED water, THEN test. Think about it, if you rinse the bowl (a pretty small volume) with tap water that is in the hundreds of TDS, some residue will be left so that when you measure the small amount of high TDS with large amount of low TDS, you, or at least I, get a reading of around 6-7... Basically, just rinse the test container with RO/DI water a few times BEFORE you test. My HTH Link to comment Share on other sites More sharing options...
YBeNormal June 4, 2009 Share June 4, 2009 No, I don't think this is related to the city flushing the water supply. I would try reseating the RO membrane. Test the TDS of your tap water and then test the TDS of the RO water after first letting it run off a gallon or so. The TDS after the RO membrane should be less than 10% of the tap water reading. Ideal would be about 2%, but that depends on water temperature and pressure. If you are still seeing high TDS after reseating the RO membrane, it may have dried out during storage and should be replaced. FilmTec membranes are sold by AWI and most other reputable dealers and are considered to be some of the best in the consumer market. I haven't looked lately but I think a 75 gpd membrane from AWI is only about $40. That's pretty cheap when you consider that they typically last 3-5 years. Don't buy cheap no-name RO membranes. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now