NEW RODI system issues

[Herndog]

Brand new Typhoon 5 running GAC in place of first carbon due to chloramines. Membrane verified with Dow app to be genuiune.

Pressure 50 PSI
Water temp 57.2 f
Tap TDS 272
Unit comes with a 800 flow restrictor
Appears to be dumping 3 gallons for every one gallon pure

After membrane 18 - 20 after flushing and then running for 8 hours (started at 27)
1)10 micron sed filter
2)refillable activated carbon
3)1 micron carbon block
4)BW60-1812-75 RO membrane
5)refillable DI resin

Old unit was a RODI Buddie with a vontron 50gpd and got a similar rejection rate of 93%. I was expecting 97-99 with dow.

 

[Zalick]

I'm no expert, but I believe your water temp decreases efficiency. Following along because I have cold water too.

 

[Vinny Kreyling]

Water temp really affects RO performance.
Pressure is a little on the low side too.
A 10 micron sed filter IMHO is too big allowing a lot of stuff into the carbon block.
I run 0.5 filters before the membrane. If you don't pack the carbon & DI resin real tight they do not work right either.

 

[Herndog]

I question that 10 micron sediment filter myself. It was originally followed by a 5 micron carbon block then a 1 micron carbon block. I am concerned with the 5 micron carbon block replaced by GAC for chloramine removal the GAC will get clogged up.

Nevertheless with a 1 micron prior to the membrane the membrane performance shouldn't be affected since it is rated for up to 5 micron. This membrane is rated at 50 for incoming pressure. Watching BRS videos their membrane operated much better at 30 PSI than mine is at 50 PSI.

I am wondering if it is a crap membrane from the factory. I have read that TDS removal is better at lower temperatures just slower.

 

[mcgyvr]

Sorry your post really isn't clear...Is the problem that your source waters tds is 27ppm and you are getting 18-20ppm after the ro membrane?

Was pressure measured at the source or just prior to ro membrane?

 

[Herndog]

Your reading comprehension isn't clear - being blunt - source is 272 as written in first post and I am getting 93% rejection versus rated 99%. I figured I would get a better rejection rate than that which is the same as my old RO buddie with Vontron membrane.

Pressure at membrane input.

Thank You

 

[Herndog]

Correction - where I have said activated carbon I should have said Catalytic carbon.

Water in this area is purchased from Kansas City Mo. and is considered moderate hardness.

I am wondering if the "fines" from the Catalytic carbon which I did flush till clear are still getting past the membrane raising TDS at exit. Water after DI is zero. DI will be gone fast with 18 - 20 out of the membrane.

 

[mcgyvr]

Sorry...Yes..I missed the tap tds in the first post...

With that source water temp and membrane I would expect a bit higher rejection too.. Yes rejection is typically a bit better at colder temps but production rate is less..
Have you tried to reseat the membrane?

 

[Herndog]

Yes sir - reseated a couple times then tried a different filter can with the same results.

 

[alton]

https://www.bulkreefsupply.com/75-gpd-reverse-osmosis-membrane-dow-filmtec.html
I use this one and change it when I change the rest of my filters since its half the price of the better membranes. My TDS is close to yours and my PSI is around 45 - 50. I get a TDS of 2 most times and 5 worse case after membrane. I also run 1 micron sediment filter. If you run large amounts of water you might want to think of using the Chloramine Monster from BRS. You will find the 2" x 10" do not last very long.

 

[mcgyvr]

https://www.bulkreefsupply.com/75-gpd-reverse-osmosis-membrane-dow-filmtec.html
I use this one and change it when I change the rest of my filters since its half the price of the better membranes. My TDS is close to yours and my PSI is around 45 - 50. I get a TDS of 2 most times and 5 worse case after membrane. I also run 1 micron sediment filter. If you run large amounts of water you might want to think of using the Chloramine Monster from BRS. You will find the 2" x 10" do not last very long.

Thats the same membrane they are using..

I would contact Airwaterice and see if they can provide any assistance..
Its possible that you got a membrane that isn't performing as well as it should be..
Maybe they will send you another to try out..

Its also possible that there are inaccuracies in testing or that some part of your waters chemistry is causing this too..

 

[alton]

Thats the same membrane they are using..

I would contact Airwaterice and see if they can provide any assistance..
Its possible that you got a membrane that isn't performing as well as it should be..
Maybe they will send you another to try out..

Its also possible that there are inaccuracies in testing or that some part of your waters chemistry is causing this too..

I would of assumed he would of contacted airwaterice first before coming on here first? Got a bad membrane, easier to replace for $34.99 than worry about it. Airwaterice is $39.99 and not sure what their shipping cost are? If not go back to seller first and ask for a replacement, especially since you bought a new system.

 

[Opus123]

OP, can you test the tds after the carbon block to see what the tds is right before the membrane. That will tell us if the carbon filters are adding to the tds.

 

[Herndog]

OP, can you test the tds after the carbon block to see what the tds is right before the membrane. That will tell us if the carbon filters are adding to the tds.

Good idea.

AWI said it is performing excellent based on these numbers... Maybe right but I thought it would be closer to 97 98 99.. It is all about saving DI resin. AWI rep told me he didn't believe people posting were getting 99 rejection. They also said prefilters do nothing for TDS good or bad.

 

[Vinny Kreyling]

Spectrapure advertises a very high rejection membrane @ a premium.

 

[mcgyvr]

Spectrapure advertises a very high rejection membrane @ a premium.

Sure they "bin" the membranes (aka find the ones that are proven to be achieving the higher rejection and sell them as that)..

 

[Opus123]

Good idea.

AWI said it is performing excellent based on these numbers... Maybe right but I thought it would be closer to 97 98 99.. It is all about saving DI resin. AWI rep told me he didn't believe people posting were getting 99 rejection. They also said prefilters do nothing for TDS good or bad.

The part about the prefilters and TDS is correct assuming they are good quality and performing as they should. Not sure why AWI doesn't believe people. My tap tds runs between 400 and 450 depending on time of year and my tds after my ro membrane runs between 4 and 6. I'm using the sprectrapure high rejection rate membrane. They used to guarantee 99%+ but I believe they don't do that anymore.

At your current 18 tds, you will get around 250 gallons of 0 tds water from a DI cartridge. If you can get it to perform at 99%, you are looking at around 1500 gallons of 0 tds water from a di cartridge.

 

[Herndog]

Installed a new pressure gauge - water pressure to membrane after prefilters is showing as 70 PSI. Did you know that the pressure changes with different sized restrictor or open fast flush - you may say DUH but what is the proper way to test water pressure? Will be installing new TDS meter soon.

 

[Herndog]

Update and why I have been here 13 years but do not post much. I received my new HM dual inline TDS meter tonight. I also received a new 1 micron GE Z sediment filter and 550 fast flush restrictor.

I installed the new TDS meter and tested and got 5-8 out of membrane and 0 from DI cart.

I installed the sed filter and 550 restrictor and pressure went to 75 and new TDS meter reading 5-8 out of membrane. Was testing 14-18 with two 10 year old handheld HM TDS meters.

So per the inline TDS meter Tap in is 268 and RO membrane out is 5-8 usually 6-7.

I guess the old meters are reading about 8 too high unless the new one is off. I get a 97 plus rate based on these numbers. So over the 96 min for this membrane. So false alarm. Thanks

 

[moondoggy4]

Check your water closets to the source, make sure nothing else is on in the house. The pressure varies during the day depending on how many people are using water dwon the street.