New RODI unit - Please help!!

[monti mike]

Hi everyone! I got a new BRS 4 stage water saver plus RODI unit and I’m struggling with the TDS in the final RODI phase. I hooked up the system last night and it ran for 10 minutes with the flush valve open to rinse out the system. Then I closed the flush valve and let water run through at 65 PSI for the 2 hours like the instructions recommended. What was frustrating is that the TDS leaving the RO membrane never dropped below 3 ppm and the TDS leaving the DI section never dropped below 2ppm. I read that a new RODI unit can have higher TDS for 24 hours... is that what you all typically experienced too? Do you think I’m safe to use that 2 TDS RODI water?? I’m located in Minneapolis and checked out the water report, there’s 2.6 - 3.5 ppm of chloramine in the tap water. BRS recommends at least the 5 stage if there’s Chloramines so I think I know my answer already

 

[mike550]

Do you think I’m safe to use that 2 TDS RODI water?? I’m located in Minneapolis and checked out the water report, there’s 2.6 - 3.5 ppm of chloramine in the tap water. BRS recommends at least the 5 stage if there’s Chloramines so I think I know my answer already

Two quick suggestions. First, I'm surprised it's showing 2 TDS coming out of the DI stage. Not sure if I would feel comfortable using it because while it may be "low" TDS, you don't know what the TDS is. Second, if your water has chloramines, I think BRS suggests a 5 stage because you change the first carbon filter with something that filters out chlorine / chloramines.

 

[Mjl714]

I would simply add another carbon housing specifically to remove chloramines, and place immediately before your current carbon housing.

 

[DWill]

Your best bet s to all BRS, they’ll get you straightened out in a couple minutes. My guess is you’ll pick up two universal carbon blocks. Sounds like you’ll need one of those with a new canister as well. You may also need to upgrade the sediment filter to the 1 micron filter. Basically sounds like you’ll need to add
the parts to upgrade to 5 stage system. But they’ll know better than me.

Also, if you’re running the water saver kit the TDS coming out of the RO will be slightly higher than with a single membrane. This is because you’re feeding concentrate into the second membrane. Still the DI should bring it down to 0. You’ll burn through DI resin at a slightly faster pace as well, and the RO membrane will be have to be replaced a little sooner As trade off for saving water.

In my case I opted to not go with the water saver for my system because I doing the math it looks like I’ll save more by buying less filter media then using less water. I did however add a second DI canister.

 

[PatW]

Well, I cannot say if 3 tds post RO membrane is bad or not. I think that BRS RO membranes have about a 98% rejection rate. That means if your source water is 150 tds, you can expect 3 tds out of the RO membrane. If you have 300 tds source water, you should get 9 tds.

But any water coming out of the DI cartridge should be 0 tds. A high tds water coming in will just deplete it faster.

 

[monti mike]

I used the TDS meter from my zero water filter and it’s saying my tap water is 122. So if I the RO membranes are supposed to remove 98% of TDS then the RO out looks correct around 3 TDS. So something must be off with my DI resin chamber... Maybe it’s not packed correctly?

 

[PatW]

That would be my guess. If it is not packed pretty tight, the water will tunnel through.

 

[monti mike]

Now I don’t know what to trust! The built in TDS meter says there’s 2 ppm but my handheld says zero. I’m going to let it run a bit longer to see if it zeros out on the built in. If it’s still an issue tomorrow I’ll give BRS a call. Thanks everyone for the helpful advice on this!

 

[vetteguy53081]

Be sure if you haven't to flush out and rinse new membranes/cartridges before use

 

[monti mike]

Update!

I ran the system for another 2 hours and then gave it a good flush for 5 minutes. Now the TDS meter leaving the DI chamber is finally reading ZERO! Yes!

I may still invest in one more canister for carbon because of the chloramine in my tap, but for now I’m glad I have some decent top off water.

Thanks again for all the help!

 

[DWill]

You can pick up test strips and test the product water for chloramines. But you’re safer spending the small amount of money and getting another universal carbon block. The testing is that you’d have to test every time make water. All it takes is a slight increase in the amount of chloramine to exceed the ability of the single carbon block to take it. You’ll never know it’s been increased or not unless you test every batch.