RODI questions

[Kens Bees]

I’m replacing my prefilter, carbon, DI, and membrane. At the same time I’m adding two additional cartridges so it becomes a 6 stage system; one prefilter, 2 carbon, the membrane followed up by two DI canisters. I found my tds was way high recently and thought I’d scrap everything and upgrade at the same time. I have a few questions for anyone running a similar setup.

1. Where do you measure system pressure at? I put my gauge between the last carbon and the membrane and only got 22#.
2. On the membrane canister, one end has a single fitting and the other has two. The single fitting goes to the DI canisters, blue line. One of the other two goes to the drain, with the restrictor, and the other takes water in from the carbon, yellow line, right? Picture attached since they’re worth a thousand words. The white line is water in to the whole thing.
3. Finally, where would the 3 TDS sensors go now?

 

[danielm5]

I'm no expert but I believe the membrane has the input on the side where there's a single connection (where you put the blue line) and the two on the other side are the outputs, one is the filtered water that goes to DI and the other is the wastewater that goes to drain. At least that's how mine works.
I'd say the yellow line goes where you have the blue and vice versa.

 

[Casino]

Pressure I would place going into your membrane. TDS sensors... 1 into your first canister. 2 coming out of your membrane. 3rd coming out of your DI. You need to check with your manufacturer which ports in the ro membrane are the waste line and product line but it should be like you described.

 

[Kens Bees]

I'm no expert but I believe the membrane has the input on the side where there's a single connection (where you put the blue line) and the two on the other side are the outputs, one is the filtered water that goes to DI and the other is the wastewater that goes to drain. At least that's how mine works.
I'd say the yellow line goes where you have the blue and vice versa.

You’re right, I’m not sure where I got that idea from.

 

[Kens Bees]

Pressure I would place going into your membrane. TDS sensors... 1 into your first canister. 2 coming out of your membrane. 3rd coming out of your DI. You need to check with your manufacturer which ports in the ro membrane are the waste line and product line but it should be like you described.

Thanks. Going back in now.

 

[Cooper2]

22PSI?....... Did I read your post correctly? I think you're going to get poor performance with regard to waste production and burn through resin at an expensive rate. Your pressure to the membrane needs to be significantly higher. You need a booster pump that can provide higher pressure than what you're getting from your well or municipal supply. I run at 80PSI. I learned the hard way with same situation.

 

[Kens Bees]

I got the pressure up to 80 and have all the sensors in place. TDS measures 180, 14, 0. I’m going to run 20 gallons or so through it and check it all again before using any of it.

Thanks for the input guys, appreciate the help.

 

[danielm5]

Sounds good!