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RODI Help

dangalang

Supporting Member
I need help troubleshooting my RODI setup. I bought a 75 GPH BRS 6-Stage RODI kit a few months ago when it was on sale. The first DI canister is about 80% used up and I've only made at most 300 gallons of RODI water. My TDS in is 4, but it takes 15-20 minutes to get there, even after flushing for 2-3 minutes to start. I think my pressure is good at around 65 psi.

I'm in San Jose, so I'm guessing it's the chloramine in the water? My home has a water softener system, could it be that?

If the issue is chloramine in the water, should I add another stage specifically for chloramine or change one of the existing carbon blocks for something else?
 
Do you have a way to get a chlorine residual after your carbon blocks? Chloramines can nuke DI resin pretty quickly.

Also, are you certain your utility is using chloramine for disinfection?
 
Do you have a way to get a chlorine residual after your carbon blocks? Chloramines can nuke DI resin pretty quickly.

Also, are you certain your utility is using chloramine for disinfection?
I think so, I found this when Googling: https://www.sjwater.com/customer-ca...chine?-,Yes.,tropical fish store for guidance.

"Yes. In order to comply with USEPA and California Department of Health Services regulations, SJW uses disinfectants such as chlorine or chloramine. These disinfectants must be removed before the water can be used in aquariums or kidney dialysis machines. Please consult your doctor or tropical fish store for guidance."
 
I need help troubleshooting my RODI setup. I bought a 75 GPH BRS 6-Stage RODI kit a few months ago when it was on sale. The first DI canister is about 80% used up and I've only made at most 300 gallons of RODI water. My TDS in is 4, but it takes 15-20 minutes to get there, even after flushing for 2-3 minutes to start. I think my pressure is good at around 65 psi.

I'm in San Jose, so I'm guessing it's the chloramine in the water? My home has a water softener system, could it be that?

If the issue is chloramine in the water, should I add another stage specifically for chloramine or change one of the existing carbon blocks for something else?
Which carbon block did they give you? If it's this one, then you're going to wipe out your DI resin. If so, then you need the universal carbon block. That one can handle chloramines.
 
I think so, I found this when Googling: https://www.sjwater.com/customer-ca...chine?-,Yes.,tropical fish store for guidance.

"Yes. In order to comply with USEPA and California Department of Health Services regulations, SJW uses disinfectants such as chlorine or chloramine. These disinfectants must be removed before the water can be used in aquariums or kidney dialysis machines. Please consult your doctor or tropical fish store for guidance."
That's their generic statement. Here's their last annual report.
Average system chlorine residual is 1.12 mg/L for their entire system. That is low actually. Their source water and after treatment has high TDS though. Your double carbon block filters should be able to handle low residuals for a while without breakthrough.
 
Are you sure the DI is connected to the RO clean outlet and not the RO dirty outlet? 80% used that fast seems very weird.

Also how are you calculating 80%?

Finally, is the DI packed in or loose? Packed in means more resin, less channeling, better usage.

Regarding testing for residual chlorine, I bought some chlorine test strips. My understanding is they detect chloramine as well. I'm curious if others agree.

Chloramine seems like BRS buzz word for "spend more money on our filters", which I've had trouble assessing if there's truth to it. Eg if you have a universal chlorine block and DI, is it really that scary? My research implies the worst case you burn through your RO membranes fast and DI resin. I'm curious what others understand the truth to be.
 
I am located in South San Jose (Great Oaks Water) and have a 7 stage BRS RODI kit. The TDS going in is about 330 and drops down to 4 after the sediment, carbon blocks(2) and RO membrane. With the three DI canisters: 1- Cation 2-Anion 3- Mixed bed.
I have had to replace the Anion resin about 3 times before I have had to replace the Cation resin. (Not sure what's in the water that burns thru the Anion resin?)
 
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Are you sure the DI is connected to the RO clean outlet and not the RO dirty outlet? 80% used that fast seems very weird.

Also how are you calculating 80%?

Finally, is the DI packed in or loose? Packed in means more resin, less channeling, better usage.

Regarding testing for residual chlorine, I bought some chlorine test strips. My understanding is they detect chloramine as well. I'm curious if others agree.

Chloramine seems like BRS buzz word for "spend more money on our filters", which I've had trouble assessing if there's truth to it. Eg if you have a universal chlorine block and DI, is it really that scary? My research implies the worst case you burn through your RO membranes fast and DI resin. I'm curious what others understand the truth to be.
It comes pre-assembled from BRS, so I think it's hooked up correctly. There is an in-line TDS meter installed and the input water into the DI resin gets down to 4 TDS (eventually) and output is 0 TDS per the in-line TDS meter and a separate TDS probe I have.

I'm calculating 80% DI resin used up just based on the color change of the resin, not sure if that's the best way to judge that?
 
It comes pre-assembled from BRS, so I think it's hooked up correctly. There is an in-line TDS meter installed and the input water into the DI resin gets down to 4 TDS (eventually) and output is 0 TDS per the in-line TDS meter and a separate TDS probe I have.

I'm calculating 80% DI resin used up just based on the color change of the resin, not sure if that's the best way to judge that?
Maybe take a pic of your resin and upload?
 
Maybe take a pic of your resin and upload?

PXL_20240223_034228852.jpg
 
RTFM - I think I figured out the issue?

Membrane Flush:
Plus Systems include an integrated membrane flush valve. Flushing the membrane for 1-2 minutes before and after each use is recommended. Avoid extended periods (longer than 2-3 weeks) between operation, as stagnant water can lead to bacterial growth on the membrane, causing damage. If water production needs are less frequent, it is still advisable to operate the unit periodically to flush the system of stagnant water.


I definitely go longer than 2-3 weeks between making batches of RODI. So maybe my RO membrane is damaged and that's why it has been taking so long to get to single digit TDS before the DI stage? Since the TDS is relatively high and takes awhile to get to 4, that could be the reason my DI resin is getting used up so quickly? Now if the problem is with my RO membrane due to stagnant water, can I fix it by flushing a bunch of times or do I need to get a new RO membrane?
 
I am in Saratoga which I believe is served by the same water service as San Jose. I also have a whole house water softener. I generate zero TDS RODI without issue. Something must be wrong with the unit BRS sent. I am on the road now but can post a picture of what my BRS setup looks like tomorrow.
 
I need help troubleshooting my RODI setup. I bought a 75 GPH BRS 6-Stage RODI kit a few months ago when it was on sale. The first DI canister is about 80% used up and I've only made at most 300 gallons of RODI water. My TDS in is 4, but it takes 15-20 minutes to get there, even after flushing for 2-3 minutes to start. I think my pressure is good at around 65 psi.


300 gallons in San Jose is asking a lot out of your system. Our tap water here is over 450ppm. Change out your resin more often and you'll be fine.
 
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