RODI question. Higher TDS going into DI canister

[Webmanny]

Hey guys,

I've been using my eBay RODI 5 stage filter for about a year with the filters it came with and never had any issues. About a month ago, I started getting some TDS reading on the final TDS sensor going out of the RODI. Therefore, I bought all the filters, membrane and DI resin from BRS to replace them all.

Now that I have all new filters, membrane and resin, I noticed that I get higher readings before the DI canister than what I used to get before. I used to get 14 to 18 TDS reading before the DI resin, but now they climb to almost 300 when I first turn it on and slowly come down to about 30.

Did I do something wrong when installing the filters or is this normal with the BRS 5 stage kit and 100GPD membrane?

Please note that the membrane I had before was also 100gpd.

 

[FloMotion]

Hmmm... Hard to say, usually the sediment, carbon block, and DI will exhaust long before the membrane. That being said, I would point to the membrane as the issue, given your filters were replaced in the same canisters as before.

 

[CuzzA]

When's the last time you calibrated your TDS meter?

 

[Webmanny]

Hmmm... Hard to say, usually the sediment, carbon block, and DI will exhaust long before the membrane. That being said, I would point to the membrane as the issue, given your filters were replaced in the same canisters as before.

Maybe it was not properly set in the container. I will try removing it and inserting it again,

 

[Webmanny]

When's the last time you calibrated your TDS meter?

I don't think I have ever calibrated it, but I took out the line coming out of the membrane and measured with a portable TDS meter I got online and I got the same reading. Therefore, this is not the issue.

 

[oblio]

Not sure on the original question however the climbing number that comes back down I believe is normal. That's the purpose of the flush kits they sell. When the system sits still there is no pressure holding the bad thing to the outside of the membrane, so they will dislodge and contaminate the water in the housing. When you first turn the system on you will see a higher than normal reading as everything settles back in. I don't get numbers like yours but if I don't flush the system for about a min before using my number will climb to about 50 then come down to about 3 after an hour or so of making water my pre DI is 1 or 2. Maybe look into a flush kit to avoid that spike.
Another thing I noticed is don't make water when everyone is up and intermittently using water this will cause resource fluctuations unless you have a pump on the system. I make water overnight to avoid these pressure drops.

 

[Webmanny]

Very good point. I think that is something this membrane may suffer from. I will look into a flush kit to see if that improves anything.

 

[Ted_C]

There's a few things here:
Remember - Carbon is pretty friable (flakes easily). Even when I buy quality carbon cartridges from Spectrapure - you have to let them run for an hour (without the DI stage) to remove all the lose particles. It's not a flush kit for this - it's just letting them run with water to remove anything from manufacturing / shipping that might have broken lose.

Also - BRS is crap (in my own opinion). almost everything I buy there is bad. It's probably impossible to tell - but you may have gotten coconut carbon instead of bituminous carbon. While this alone may not add to your TDS - it works less efficiently than bituminous carbon blocks. There's the possibility of any number of other issues with filters from BRS or less than reputable dealers. Also remember that they have different quality filters apparent from their own in-house chloramine testing stuff they did a couple years ago. Remember - they are buying the cheapest items possible to keep low prices for their customers.

Check what you bought for micron ratings. Maybe you've gone to a bigger micron rating than you intended? I run a 0.35 micron pleated sediment filter and 2x 0.5 micron carbon blocks.

 

[Buckeye Hydro]

Hey guys,

I've been using my eBay RODI 5 stage filter for about a year with the filters it came with and never had any issues. About a month ago, I started getting some TDS reading on the final TDS sensor going out of the RODI. Therefore, I bought all the filters, membrane and DI resin from BRS to replace them all.

Now that I have all new filters, membrane and resin, I noticed that I get higher readings before the DI canister than what I used to get before. I used to get 14 to 18 TDS reading before the DI resin, but now they climb to almost 300 when I first turn it on and slowly come down to about 30. Did I do something wrong when installing the filters or is this normal with the BRS 5 stage kit and 100GPD membrane?Please note that the membrane I had before was also 100gpd.

Feel free to give us a call when you are in front of the system if you'd like help troubleshooting!

Russ
513-312-2343

 

[Webmanny]

Feel free to give us a call when you are in front of the system if you'd like help troubleshooting!

Russ
513-312-2343

I appreciate it. I may give you guys a call soon. I took everything apart this past weekend to make sure I didn't miss anything during installation and I confirmed everything is properly installed and the membrane is properly installed in the canister, but I still get higher TDS readings going into the DI resin.

I just received a flush kit I got online and I am planning on installing it this weekend to see if flushing the membrane helps.

 

[Buckeye Hydro]

You're aware of TDS creep, right?

 

[Webmanny]

You're aware of TDS creep, right?

I was not aware that it was called that, but I think I purchased the flush kit with the goal of accounting for that. I just still wonder why this did not happen with the filters that came with the unit. Those filters would creep up to maybe 14 to 18 TDS prior to the DI resin, but these climb all the way to the 300 range and it is killing my resin really quick.

To give you an idea, the kit I had before lasted about a year before I started to see TDS readings of 30 prior to the DI resin. With this one, I see TDS of over 300 when I start it up from day 1.

Regardless, I will install the flush kit this weekend and let it flush for a while prior to making RODI water. Thank you all for your assistance.

 

[Buckeye Hydro]

Flush kits address the waste water side of the RO - the high pressure side.

Addressing TDS creep is best done, if you're going to do it manually, with a DI bypass. These are two very different things.

 

[Webmanny]

Got it. I did some research and found a video that talks about it and explains it. I will also get a 3 way valve to account for this prior to making fresh water. Thank you for the suggestion.

Does this look like the correct valve to install prior to the DI resin cartridge?

 

[Buckeye Hydro]

http://www.buckeyehydro.com/3-way-valve/

You may also want two or three 1/4" swivel elbows to make the tubing runs clean:
http://www.buckeyehydro.com/swivel-elbow/

Russ

 

[Webmanny]

Got it. Thanks again.

 

[robthorn]

I would return that ro membrane. It is complete junk and will cost you more in resin over the nexy year than it would to throw it in the trash and by a good guaranteed membrane like the 99% spectrapure. If Buckeye has a guaranteed comparible membrane then I say give your money to them for being helpful.
You will save a ton of money paying just a few more $'s for a 99% membrane.
Sediment and carbon are not likely to drop your tds since they are not meant to remove dissolved solids. At least not enough to matter. Saying that you should use .5 micron or less sediment and carbon blocks to extend the life of your membrane.
Just my opinion of course.

 

[Buckeye Hydro]

We do have the MAXR Membranes - same spec's as the other vendor's.

 

[robthorn]

Good to know Buck. ;-)