RODI Unit Questions

[Mock]

A month or three ago I changed out the whole units inners.

RO, all the filters, and DI.

I noticed I was eating through DI resin like crazy.

I really paid it no mind because every time I would look at the out it was 0.

However last night I checked it because the DI looked exhausted and it was reading 24, so I flipped the switch to what was coming in and it was reading 26.

Question is, why isn't the filter part of the canister catching more than 2 tds even if the DI media is out.

The sediment filter on the first stage looks clean and clear not orange like it gets over time, the carbon sediement filter looks clean like new almost, and the carbon I suppose in the other doesnt seem to be nasty.

The whole thing looks clean but I am still not filtering anything out.

Is it the RO membrane? I have read where I should have flushed the system before hooking it up, maybe I dont have it seated I have heard this too but it seemed to be working fine before.

Really had me scratching my head last night. Also have noticed a rise in phosphates in the tank too from .02 to .05.

 

[Shaummy]

When you said "Flipped the switch to what's coming in" what were you measuring..the house/input water or what was coming out of the RO membrane into the DI cartridge?

 

[Mock]

Whats coming in from the house.

I have it on whats the in line from the tap and the out line after the DI to the tank.

 

[Mock]

It had me scratching my head because I was sure that our water was more than 24 in tds.... I dont recall or have it written down but I can remember it being in the hundreds

This is why I am stewing over this issue. I really cant put my finger on the exacts.

 

[Mock]

Anyone?

 

[Opus123]

Do you have a handheld tds meter or know someone that does? Maybe a lfs that has one that you could take your tap water in get the tds reading. Hard to say if something is wrong if we don't know the correct reading of the tap water and the water after the RO membrane. FYI, the carbon and sediment filters will not lower the tds. They are their to take out the large particles and the carbon takes out chemicals that could harm the RO membrane. The RO membrane does most of the work of lowering the tds. If your tap water really is reading 26 then the water after the RO should be reading 1 or 2.

 

[sleepydoc]

Are you sure you installed your RO membrane properly? I would check the TDS of the tap water, the water before the RO membrane and the water after the RO membrane. I wonder if you didn't install the one of the new filters properly, so water is not getting completely filtered before the DI resin

 

[Browndawg80]

Sounds to me like your TDS meter is hooked up wrong. The IN reading should be after the main membrane and the OUT reading should be after the DI. The number going into the sediment from the source is meaningless. The way you have it setup now is not helping you to know if the membrane is exhausted.

 

[Browndawg80]

Make sense? My guess is that your membrane needs replaced. You don't know this because you are not allowing your TDS meter to tell you because you are using the IN to measure your source water from the tap. We know for certain that the number coming from the source is going to be a high number and will always be a high number regardless. If you forget about that reading and hook the IN reading up to read after the membrane then you would know if your membrane is bad or the DI needs replaced.

If you hook it up like I'm describing and get a number like 002 ( or similar) after the membrane but before the DI and then get 001 after the DI then you know it's time to change the DI. However if you get a number like 035 or something similar after the membrane but before the DI then you know that the membrane has not been working properly and the DI has been picking up the slack for it which explains why you have been burning through DI's so frequently.

If the number coming out from the membrane before the DI is not zero don't worry as this is normal and the DI will polish it down to 000 before it goes to your resovoir. At the end of the day the only number that really matters is the OUT from the DI. Hope this helped.

 

[zachfishman]

are you sure you installed your ro membrane properly? I would check the tds of the tap water, the water before the ro membrane and the water after the ro membrane. I wonder if you didn't install the one of the new filters properly, so water is not getting completely filtered before the di resin

+1

 

[Opus123]

Any updates Mock?

 

[Opus123]

Make sense? My guess is that your membrane needs replaced. You don't know this because you are not allowing your TDS meter to tell you because you are using the IN to measure your source water from the tap. We know for certain that the number coming from the source is going to be a high number and will always be a high number regardless. If you forget about that reading and hook the IN reading up to read after the membrane then you would know if your membrane is bad or the DI needs replaced.

If you hook it up like I'm describing and get a number like 002 ( or similar) after the membrane but before the DI and then get 001 after the DI then you know it's time to change the DI. However if you get a number like 035 or something similar after the membrane but before the DI then you know that the membrane has not been working properly and the DI has been picking up the slack for it which explains why you have been burning through DI's so frequently.

I disagree. You have to know your tap water to know if the membrane is working correctly. In your case, if it was reading 2 you would think that is great but if his tap is only 20 then it isn't because it means his RO is running at 90% efficiency when a good unit should be closer to 96 or 97. I'm not sure how much his tap varies but I've seen mine in low 200's and close to 500 in the summer. If he was only reading after the membrane he might think it needed replacing because the tds reading was going up when in actuality it was the tap water that was going up in tds.

 

[Mock]

Havent really messed with it....

I replaced everything like I said a couple months ago, there is no way a RO membrane can deplete that rapidly.

Like I said too, the output was at 0 before, I just hit the button on my way to the tank and was kinda shocked.

flipping the switch to the in side, which is my tap water was only 29 or and the water coming out of the whole system was around 27.

My only guess is something has failed. I was going to tear it apart tonight.

I will let you guys know what is going on.

 

[Shaummy]

As others have said, you really need to know the post RO number to isolate what's going on. The DI could have been masking a high TDS coming out of the membrane and would exhaust pretty quickly. I generally get 4-5 out of the RO stage, but I don't really know what my input number is.

 

[sleepydoc]

Havent really messed with it....

I replaced everything like I said a couple months ago, there is no way a RO membrane can deplete that rapidly.

If your sediment and/or carbon filters were 'leaking' and not filtering the water appropriately it's possible the RO membrane could get trashed quite quickly.

 

[Mock]

I dont get why you need the number after the RO unit....

The tap water is going in at 029

If its coming out after the DI chamber at 027 the s*(&t isnt working.

Either the BRS RO membrane is a POS or something is jacked up.

Two months ago this thing was reading 000 TDS on the out line, its the only one I normally pay attention to.

I didnt get a chance to tear it apart this weekend, I will open it all up this week, maybe today and see if something changed but its hard to understand why I am having to rip it all apart when like I said, it was reading zeros not that long ago with all new sediment filters, RO and DI.....

I dont really know what could have changed in such a short period but now I have to break it all down to figure it out.

 

[Shaummy]

I guess if you want to make assumptions...then your RO membrane is toast, or not installed properly. It passed 29 TDS water right to the DI media..which could keep up for a while..but got exhausted being fed that high of a TDS.

The RO out number could have confirmed that analysis..but there you have it I guess. Need to look at the membrane and make sure it's seated properly and it has a flow restrictor on it that matches the membrane you installed.

That said..if you make any changes....you will still want to check the TDS of the output of the RO membrane to make sure it's reducing the TDS like it should.

 

[Mock]

Well I mean, this thing obviously isnt either way, even if the TDS was on the out line of the RO membrane.

 

[Browndawg80]

How old is the membrane? I have reread your posts and see that you have recently replaced the sediment, carbon and DI but see no mention of the membrane other than the fact that you got it from BRS.

Also how often do you normally change the sediment and carbon? I've been under the impression they needed to be changed every 6 months to prevent damage to the membrane. It's possible if the membrane was already 2-3 years old and you weren't changing the sediment and carbon frequently enough that the membrane is simply now exhausted.

 

[Mock]

I changed it ALL about 3 months ago.... RO, Filters, the works.

It was working fine and reading 0, It not on my normal check list its just something I click on every now and then, I clicked and to my surprise it was reading 025 or so.....

It shouldnt be reading this, It ran better before I replaced everything. I dont understand it. Why one would go from working fine to not working a couple months after.

That is the issue.

Why was it working a short time ago and now its not when EVERYTHING is new......