Aqua RX RO/DI Unit Optimization

count krunk · Jan 30, 2019

Hello everyone,

i recently picked up a 200 GPD 6 stage unit. it has 4 canisters and 2 RO membranes.

I am trying to optimize its performance. I have a few questions about it.

the current flow paths:

Filtered line
in > sediment filter ( i think) > carbon > some square device > tee (goes to the pressure gauge and then flows onward) >towards another tee (here is splits to go into both RO membranes) > RO outputs combine via another tee > check valve > tee (TDS meter than flows onward) > DI > DI > exits unit > tee (TDS meter than flows onwards) > outflow line

Waste line
both waste lines come out of the RO membranes > combine via tee > manual flush setup valve > tee to combine into the singular waste line

I watched the BRS Tv video about dual RO membranes and I'm a bit confused. To me, it would make the most sense to have the filtered of the first flow into the input of the second. In the video, they have the waste of the first flowing into the second. Could someone expand on this setup?

Here is the device in question

the manual flush line

the RO outputs

Also, opinions on it better to run dual DI or Dual carbon blocks? Eventually, i will add another stage and run both.

thanks for your help

Water Dog · Jan 30, 2019

Do you know what your tap TDS is? It looks like your unit is running it’s RO membrane in parallel, whereas the BRS watersaver video has the RO membranes running in series. If your tap TDS is very high, even by BRS’s own admission, it really doesn’t make sense to run your membranes in series as you’ll be ripping through the second membrane quite quickly.

count krunk · Jan 30, 2019

i have a TDS meter, i'll test my tap when I get home today.

I would guess its 150-300.

count krunk · Jan 30, 2019

anyone have a guess as to what that squareish device is?

Water Dog · Jan 30, 2019

It’s an automatic shut off valve. If working properly (they should probably be replaced annually) it will shut off flow through the RODI unit when the clean water line is tshut off off by a float valve in your RODI clean water container. If you didn’t have one, the flow to the container would stop, but the wastewater line would continue to flow.

count krunk · Jan 30, 2019

thank you water dog!

I imagine it could use with being replaced. I'll rewatch the BRS RO video and reconfig the lines. I will most likely need to install a booster bump before I make that change though. I want to install one anyway, but not in the budget at this point in time.

I am also going to change the TDS meter from reading the waste to reading the water pre DI and post DI. I can measure the TDS of my water whenever with my TDS tester. I think pre and post DI TDS numbers is more useful information.

Thoughts?

Water Dog · Jan 30, 2019

Pre and post DI readings are optimal. I would also look into adding a 3 way valve between the RO and DI stage.

https://www.bulkreefsupply.com/3-way-ball-valve-with-john-guest-1-4-push-connect.html

Upon restarting your RODI unit, run the system with the first 3 or so minutes of RO water going down the drain, because upon startup, there will be abnormally high TDS in the RO wate... this is called TDS creep. You can see it on your post RO TDS meter. After about 3 minutes, the TDS creep water will be flushed out and you then flip the switch to the 3 way valve rerouting water back to the DI stage. This will do wonders in prolonging the life of your DI resin.