RODI Issues

[Topreefer92]

Hi All,

So I have been having an issue with TDS coming out of the DI stage at like 12 to 13. This has happened intermittently when I change out the DI resin in the system. I am running a BRS 4 stage deluxe system with 2 RO membranes. The system flushes once an hour and I flush it at the beginning of production for any TDS creep. The membranes are only a year old, sediment and carbon block were changed 2 months ago. The DI resin every time I change it is packed and stamped down to the point it is harder to get the lid on, so it is packed down. I have reseated all the canisters and removed any air form the system. It has been running now for over an hour with this still going on. Do I need a new system, as this one is almost 10 years old? I just dont understand how replacing the DI Resin will cause this.

Thanks for your time!

 

[Biglew11]

I've seen this with new di resin. Do you know the tds between the ro membranes and the di stage? Also what tds are you starting out with?

I have mine set up as the 7 stage unit with 3 di stages, cation, anion, then mixed. I have a tds sensor at the first Input, then after the ro membranes, I usually see about 3tds with the two product lines combined, then between the anion and mixed bed and always get some tds creep about 11tds for about 5 minutes after each use. I have a final sensor after the mixed bed final stage to my resivior, and never see any tds there.

 

[Topreefer92]

Hey Biglew11,

So I repacked the catridge twice and now it is down to 3 but wont go any lower. The tds between ro membranes and the di Stage is 14 that is the lowest I have ever been able to get it here in Arizona. My TDS from the tap after the water softener is around 500 (well water). The water is quite warm here so I dont know if that is affecting it but I have noticed that this unit is becoming more of a pain with this as the years go on. I am wondering if it is the cartridge and the o ring causing problems.

 

[K7BMG]

It could be just fine.
The TDS probes can and will fail.
It might behoove you to do two things.
First and simple is make sure your probes are clean and correctly positioned.
There could be debris, sediment, or other build up on the probes.
The probe pins could have been turned and in line with the T.

The pins should be on the left and right of the T when you look through the end. If the pins are in the center in line then you could have an issue.

Secondly do you have your resins in the right order?
Could it be possible the Anion is first followed by the Cation?

 

[Topreefer92]

I will clean the probes again and reposition them, the probes are only 6 months old but I can get a new one since spectrapure is local here. I only have the mixed bed resin not separate cartridges but that might be a good idea to do.

 

[K7BMG]

By your previous posts I thought you TDS meter was older as well.

That said might need to be calibrated.

 

[skim]

Have you ever changed the Flow restricter?

 

[K7BMG]

May I also recomend getting your water tested.
I am sure there is a lab close by.
You could have something in your well water that cant be pulled out by the RO/DI.
i had my well water tested just so I know whats in There to start with.

Well water can change over time.
I had this done a month or so back, cost me $185.00 and had the results in a week.
My well water always is around 175 TDS.
After the RO its 10. And the product water is 0.
I have two TDS meters on my system for redundancy.
Are you using a pressure pump?
I do and installed it right befor the RO units where the pressure is needed.
I have it set to 85psi.

In anycase I feel that there may be something in your source water that the system cant handle anymore.
The resin cartridge gaskets also may be worn and allowing water to bypass them.
I doubt you need to replace the entire unit but the cartridges should be.

 

[AZMSGT]

Call spectrapure, they are very helpful at solving water issues. Also they won’t have you just blindly changing things to make money.
Most RODI units are the same housings, mounts and tubing. The only difference in them might be filters. So there is no need to change the entire unit. The membranes and filters might need to be configured better.

 

[Topreefer92]

Have you ever changed the Flow restricter?

I have not but cant hurt to change it!

May I also recomend getting your water tested.
I am sure there is a lab close by.
You could have something in your well water that cant be pulled out by the RO/DI.
i had my well water tested just so I know whats in There to start with.

Well water can change over time.
I had this done a month or so back, cost me $185.00 and had the results in a week.
My well water always is around 175 TDS.
After the RO its 10. And the product water is 0.
I have two TDS meters on my system for redundancy.
Are you using a pressure pump?
I do and installed it right befor the RO units where the pressure is needed.
I have it set to 85psi.

In anycase I feel that there may be something in your source water that the system cant handle anymore.
The resin cartridge gaskets also may be worn and allowing water to bypass them.
I doubt you need to replace the entire unit but the cartridges should be.

I will have to look into that as my water company posts reports but are not super detailed. I do not use a pump because the PSI coming from my tap is already at 90. I ordered a couple of Spectrapure cartridges as the current one is 10 years old!

Call spectrapure, they are very helpful at solving water issues. Also they won’t have you just blindly changing things to make money.
Most RODI units are the same housings, mounts and tubing. The only difference in them might be filters. So there is no need to change the entire unit. The membranes and filters might need to be configured better.

I ordered some cartridges from them yesterday and have an email into them about this. I utilize all their media/filters since there local and I dont want to wait a week from BRS. That is awesome they do that, makes me even more happy to support a local business like that!

 

[K7BMG]

Ok so now you have confused me. LoL Easy to do maybe.

You say your on a well and yet have a water company also?
Or are you just referencing that the water company puts out a curtesy report to all the property owners.

I know there are municipal wells that will feed neighborhoods but that's not the same as your own well.
Municipal WELL water will have been processed, treated, and full of unwanted contaminants such as chloramines and fluorides for a reef tank.

 

[Topreefer92]

Ok so now you have confused me. LoL Easy to do maybe.

You say your on a well and yet have a water company also?
Or are you just referencing that the water company puts out a curtesy report to all the property owners.

I know there are municipal wells that will feed neighborhoods but that's not the same as your own well.
Municipal WELL water will have been processed, treated, and full of unwanted contaminants such as chloramines and fluorides for a reef tank.

My fault yes it is a municipal well I should have clarified that in the beginning, I apologize.

 

[Opus]

You might want to invest in a handheld tds meter. They compensate for temperature and the inline ones do not. Doubt it would cause a very big difference like you are seeing.

Make sure your DI cartridge is not installed upside down. I kept getting a tds reading after my di for months and couldn't figure out why. Finally was looking at RO pictures and realized I had the di catridge upside down.

 

[Topreefer92]

The water here in az is warmer for sure, I did test with my handheld and getting 1 coming out. The area should be facing up as I have seen in pictures on the cartridge. I am betting the cartridge is bad, picking up some new ones from spectrapure today

 

[Biglew11]

also 500 tds going into the unit is pretty high. and you did say that it is a 4 stage unit? a tds of 14 after the ro is still a 97.2 rejection rate. new Dow filmtec ro membranes are rated between 96-99 rejection rate, so your within specs of a new membrane. a tds of 14 after the di resin still sounds like the water is bypassing the resin somehow, have you checked the seal on the di cartridge? also check that stage for any signs of cracks that might let water pass unfiltered. worse case scenario you have to replace that section.

lol i was still typing my reply.

 

[Topreefer92]

also 500 tds going into the unit is pretty high. and you did say that it is a 4 stage unit? a tds of 14 after the ro is still a 97.2 rejection rate. new Dow filmtec ro membranes are rated between 96-99 rejection rate, so your within specs of a new membrane. a tds of 14 after the di resin still sounds like the water is bypassing the resin somehow, have you checked the seal on the di cartridge? also check that stage for any signs of cracks that might let water pass unfiltered. worse case scenario you have to replace that section.

lol i was still typing my reply.

After all these great conversations with everyone here I am thinking the cateidge might have bit the dust. I am going to change it out this afternoon and report back!!

 

[Scorpius]

Make sure the DI resin is packed very tight in the cartridge. You want no air gaps whatsoever.

 

[Topreefer92]

Low and behold I put a brand new DI cartridge in there and it is working like a champ. I dig the design of the spectrapure cartridge vs the BRS ones. Thanks all for the help! Case closed

 

[K7BMG]

Low and behold I put a brand new DI cartridge in there and it is working like a champ. I dig the design of the spectrapure cartridge vs the BRS ones. Thanks all for the help! Case closed

thats good.