Bad DI resin = higher TDS?

[bevo5]

I'm having some RODI issues.

First, it was super clogged and not producing...so I replaced by RO membranes on my 180GPD system. It is producing more water than I've ever seen it produce. Just pouring into the container. I ran it for about an hour and I was getting 0 TDS.

I left it overnight, and in the morning the first water out was over 100 (tap here is 30-50 at the moment). So I ran it longer but I can't get below 20.

I've tested the water out of the RO membranes and it's 4TDS. I assume the DI needs to be replaced, but is it possible that used up DI resin can increase TDS?

Just trying to figure out the move from 4 to over 20.

Thank you.

 

[LeftyReefer]

I'm having some RODI issues.

First, it was super clogged and not producing...so I replaced by RO membranes on my 180GPD system. It is producing more water than I've ever seen it produce. Just pouring into the container. I ran it for about an hour and I was getting 0 TDS.

I left it overnight, and in the morning the first water out was over 100 (tap here is 30-50 at the moment). So I ran it longer but I can't get below 20.

Your RO should remove 98% of your Tap's TDS. If your tap water is only 50 TDS, then you shouldn't see any more than 1 maybe 2 TDS out of your RO membrane as long as its good. That last 1 or 2 TDS should be removed by your DI stage.

If your Tap TDS is only 50, and you are getting 20 out of your RO membrane, then something is wrong with the RO membrane.... is it installed correctly? was it new? did you flush it out after installing it?

 

[bevo5]

Your RO should remove 98% of your Tap's TDS. If your tap water is only 50 TDS, then you shouldn't see any more than 1 maybe 2 TDS out of your RO membrane as long as its good. That last 1 or 2 TDS should be removed by your DI stage.

If your Tap TDS is only 50, and you are getting 20 out of your RO membrane, then something is wrong with the RO membrane.... is it installed correctly? was it new? did you flush it out after installing it?

So...it's a 180GPD system but I could only find 100GPD membranes, so I'm not sure if that's an issue. But they were new and installed and produced 0 TDS after flushing for about an hour.

But now, when I turn them on I get over 100 for the first few minutes, which we assume is creep. But I just can't get below 20....even though the water coming out of the Membranes is hitting 3-4. Then, when it comes out of the resin - it's 20.

I just pushed them into the tubes and reconnected everything. I'm pretty sure it's installed correctly, same as I've always done over the years.

I will say, water is absolutely pouring into the container. Exceptionally faster than I've ever seen it produce. I attributed that to being 100GPD membranes, but it's a very fast amount of water with the waste line still halfway open.

 

[r20crazy]

you HAVE to replace the flow restrictor in the ro/di unit if you went from 180gpd to 100gpd membrane. if you didnt thats the problem as the new membrane isnt working correctly.... if didnt do so you also need to replace the prefilters (sediment and carbon blocks), along with the di resin. yes bad DI resin can cause high tds.... you also may not have the new membrane seated correctly/fully, but the restrictor must be sized to the new membranes output...

clogged prefilters lead to clogged membrane, which makes high tds outa membrane which makes Di resin stop working quickly....

 

[bevo5]

you HAVE to replace the flow restrictor in the ro/di unit if you went from 180gpd to 100gpd membrane. if you didnt thats the problem as the new membrane isnt working correctly.... if didnt do so you also need to replace the prefilters (sediment and carbon blocks), along with the di resin. yes bad DI resin can cause high tds.... you also may not have the new membrane seated correctly/fully, but the restrictor must be sized to the new membranes output...

clogged prefilters lead to clogged membrane, which makes high tds outa membrane which makes Di resin stop working quickly....

Ahhh....Just to make sure I didn't confuse things... I'm going from two 90GPD membranes to two 100GPD membranes. The flow restrictor will need to be replaced for that change?

I'm getting very low TDS out of the membranes as it is. It's going up when it hits the DI resin.

 

[bevo5]

Just ran to do another test and the water comning out of the membrane is 1-3 (I have two TDS meters I'm using). The water coming right out of the DI is 15-20.

At this point I have to believe it's just the DI resin?

 

[Lonely reefer's]

Double check the DI cartridge /seals if installed correctly, internally leak pass DI cartridge?

 

[r20crazy]

Just ran to do another test and the water comning out of the membrane is 1-3 (I have two TDS meters I'm using). The water coming right out of the DI is 15-20.

At this point I have to believe it's just the DI resin?

the restrictor is fine in that case... thought you went from a single 180gph to a single 100gph membrane.....

sounds like the Di resin is spent then..... replace and all will be good

 

[Saltyreef]

If you dont have a 3 way DI bypass valve installed before the DI, i would highly recommend getting one. The tds creep that forms on the effluent clean side of the membrane will destroy/wear out your resins prematurely (even if you think youre doing something with a flush kit)

Also, have you ever tested for high c02 content?
I was burning through spectrapure mixed bed and silica buster max cap cartridges in about 100g or less before hitting 1tds on the final cartridge.

Started airating my RO water in a brute can overnight to pump back through the resins with a mj1200 and my final tds went from 10 back to 0 and havent replaced them since lol.

 

[GSnake]

I tried using a higher gpd membrane and also replaced flow restrictor as per manufacturers recommend actions, but it still never worked properly. I gave up and went back to using what the system was made for. This is rodi buddie by the way.

 

[bevo5]

If you dont have a 3 way DI bypass valve installed before the DI, i would highly recommend getting one. The tds creep that forms on the effluent clean side of the membrane will destroy/wear out your resins prematurely (even if you think youre doing something with a flush kit)

Can you explain this a bit more fully? I was trying to figure out a way at startup to have the initial bit of water go out the waste line, but I wasn't sure exactly what to setup. As you can probably tell, I know just enough about this to mess it up!

I went scorched earth and replaced all the filters. New sediment, carbon and DI - and I'm getting delicious 0TDS now.

I'm keen to upgrade the system to help with that first bit of creep.

Thanks all.

 

[Saltyreef]

Can you explain this a bit more fully? I was trying to figure out a way at startup to have the initial bit of water go out the waste line, but I wasn't sure exactly what to setup. As you can probably tell, I know just enough about this to mess it up!

I went scorched earth and replaced all the filters. New sediment, carbon and DI - and I'm getting delicious 0TDS now.

I'm keen to upgrade the system to help with that first bit of creep.

Thanks all.

At startup with fresh filters i unplug the inlet tubing from my membrane and let it flow for 5-10 mins. Turn water off and reattach the inlet tubing back to the membrane.

To negate doing this everytime to avoid tds creep i use the di bypass valve so i dont need to disconnect any tubing just simply turn the valve handle.

The 3 way valve installs inline from the clean discharge RO tubing to the inlet tubing of your DI.
Switch the valve position to flow water out the side port (bypassing your di resins) for a couple mins. Then place the valve back to the original position for flow through your resins.

The di bypass is nice cause i generate RO first to airate in a secondary containment then use a mj1200 pump to pump the airated RO water back through the resins.

3way valve

3-Way Ball Valve with 1/4" Push Connect

Control Your Water Flow with Ease Versatile 3-Way Design Effortless Flow Direction Control Ideal for Freshwater and Saltwater Systems The 3-way ball valve is a versatile and essential fitting for any saltwater mixing station. With a simple swing of the handle, you can easily turn the water...

www.bulkreefsupply.com

Fitting to attach RO tubing to MJ1200 pump

 

[ying yang]

Just had quick read through above and some good advice.apoligise if already mentioned but
When di resin is used up then it starts releasing all that it stopped getting through.
Brs has a video on this and think it says amnonia is what it collects least off so usually at top of di resin and its this it releases first.
And as you said its 3- 4 tds before di resin but 15- 20 after di resin ? It madee think of this.i will quickly try find video

 

[ying yang]

Mistake number 5 at 5.30 minutes into video.
Im not saying this was your problem but handy bit off information to know if say example your reading high amnonia readings straight after a water change as your di resin needed changing and forgot to check tds readings etc etc.
Just thought i would share but you changed all cartridges/ membrane and di resin and got 0 tds so happy days but its probably best to know how rodi unit works and when to change each different cartridge depending if getting low pressure or not 0 tds or whatever it is as when different cartridges need changing it shows a different thing so cheaper changing what needed rather than all at once.
Glad you getting 0 tds now and good luck ^_^

 

[bevo5]

Mistake number 5 at 5.30 minutes into video.
Im not saying this was your problem but handy bit off information to know if say example your reading high amnonia readings straight after a water change as your di resin needed changing and forgot to check tds readings etc etc.
Just thought i would share but you changed all cartridges/ membrane and di resin and got 0 tds so happy days but its probably best to know how rodi unit works and when to change each different cartridge depending if getting low pressure or not 0 tds or whatever it is as when different cartridges need changing it shows a different thing so cheaper changing what needed rather than all at once.
Glad you getting 0 tds now and good luck ^_^

That's interesting. I Just always figured an exhausted DI filter would just stop being effective and we'd see TDS creep that way. But it actively releasing stuff is a whole new level, and reason to keep checking.

Feeling good with all new filters now! Can finally top off these tanks.

 

[ying yang]

That's interesting. I Just always figured an exhausted DI filter would just stop being effective and we'd see TDS creep that way. But it actively releasing stuff is a whole new level, and reason to keep checking.

Feeling good with all new filters now! Can finally top off these tanks.

As i say it may not off been your problem but first thing i thought off when you said what you said either way its a very informative intersting video from the brs team so as much information we can gather along the way while we enjoying our tank,then the better i say ^_^

 

[Saltyreef]

That's interesting. I Just always figured an exhausted DI filter would just stop being effective and we'd see TDS creep that way. But it actively releasing stuff is a whole new level, and reason to keep checking.

Feeling good with all new filters now! Can finally top off these tanks.

Forgive me for speed reading but did you ever measure your product to waste ratio after replacing membranes with larger ones?
You should be around 4:1.

 

[Biglew11]

Di ressin is an ion exchange proces. It exchanges hydrogen ions in place of the stuff it captures.
When used up it will start to releas the stuff it initially stopped. Starting with stuff with the weakest bond first, usually amonia.

 

[KStatefan]

If you dont have a 3 way DI bypass valve installed before the DI, i would highly recommend getting one. The tds creep that forms on the effluent clean side of the membrane will destroy/wear out your resins prematurely (even if you think youre doing something with a flush kit)

That seems to be a common misunderstanding what a "flush" valve does.

 

[r20crazy]

Forgive me for speed reading but did you ever measure your product to waste ratio after replacing membranes with larger ones?
You should be around 4:1.

not if the dual membranes are in series... could be 1:1. but OP didn't say... at any rate OP replaced filters and DI and its fixed