RO /di problem

[Carpn]

Hi, can anyone help please i have a 4 stage RO/DI setup and i am getting TDS reading at 3ppm after going through DI Resin. To give more details, incoming water is mains water at 3.5 bar. First stage is sediment filter (just replaced), second stage Carbon (also replaced), membrane, then finally DI. i cannot seem to get Zero on the system. I resisted the TDS inline to before the DI and i get a reading which fluctuates between 6 and 3, incoming reads 325ppm. Is the DI resin depleted or is the membrane trashed as well? Sorry i meant to say all TDI readings taken after 20 mins of running.

do i need to add anything to my set up.

Thanks

 

[Reef.]

Two things to try, pull out the tubing before the resin and test the water, your membrane will have a rejection rate printed on it, should be around 95%, if your tap water is 300 tds you should be getting a reading of less than 15 after the membrane and before the resin, the resin should bring it to zero, you need to rinse the container if not using an inline tds meter, as the container will raise the tds, if using inline and you get less than 15 after membrane then your resin is probably not compacted enough.

 

[thatmanMIKEson]

Two things to try, pull out the tubing before the resin and test the water, your membrane will have a rejection rate printed on it, should be around 95%, if your tap water is 300 tds you should be getting a reading of less than 15 after the membrane and before the resin, the resin should bring it to zero, you need to rinse the container if not using an inline tds meter, as the container will raise the tds, if using inline and you get less than 15 after membrane then your resin is probably not compacted enough.

That is good information! I see the inline tds is on the final product line, I would also do like suggested and test before and after D.I with the same inline tds and see what the difference is. And if it's fine and just because you have high incoming tds, maybe you could get an add on di cartridge with a mixed resin to polish off the remaining tds.

 

[Carpn]

That is good information! I see the inline tds is on the final product line, I would also do like suggested and test before and after D.I with the same inline tds and see what the difference is. And if it's fine and just because you have high incoming tds, maybe you could get an add on di cartridge with a mixed resin to polish off the remaining tds.

Thanks both . The inline TDS in the photo is pre DI Resin, i then moved the TDS to after the DI Resin stage (You can just see the unconnected blue pipe on the Right Hand side) the reading post DI was still 3 TDS, I’ve since disconnected the DI Pod and checked the packing which all appears (Tapped the pod several times). So yes i’m going to add a second DI Pod, possibly change out the DI Resin in the first pod. What is a ‘mixed‘ Resin please?

 

[thatmanMIKEson]

Bulk Deionization Resin (Color Changing)

Why does BRS recommend this? We recommend color changing resin for the fact that it will physically change colors as it gets exhausted. That allows you to monitor the consumption of the DI resin and know when to change it out. If you have a TDS meter we still recommend color changing resin as...

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Single Deionization Canister with DM-1 Dual TDS Meter

Single deionization add on canister kit complete with Dual TDS Meter and pre-packed color changing DI cartridges! Dimensions - 14" x 6" x 5.5" Dual TDS Meter already installed Perfect for adding additional DI stages to your RO system Cartridges come with canisters full of Color Changing DI...

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[Gtinnel]

If your source water is 325ppm and after the membrane is 3-6ppm then your membrane is working, which means the issue is with your di resin.
From what I’ve always heard you are not supposed to leave your di canister horizontal because the water can flow through it with filling up the canister. Which would essentially mean you’re only using half of the resin.

 

[Carpn]

If your source water is 325ppm and after the membrane is 3-6ppm then your membrane is working, which means the issue is with your di resin.
From what I’ve always heard you are not supposed to leave your di canister horizontal because the water can flow through it with filling up the canister. Which would essentially mean you’re only using half of the resin.

That makes sense to me ok so will change this too thanks

 

[Gtinnel]

That makes sense to me ok so will change this too thanks

Haha I just realized I had a typo. It should’ve said the water can flow through without filling the canister full of water, but it seems like you understood what I meant even with the typo.

 

[PHXHobbies]

Horizontal DIs will "channel" water flow so the best recommendation is a 10" assembly which has the clear housing, wall mount bracket, and DI filter. Some come with a TDS meter which is a plus

 

[Carpn]

Thanks guys, so I’ve modified the whole setup and added the DI 10’’ assembly also a float in the bin to stop flooding the garage (Of course). Now TDS reads zero. - finally. Appreciate the help guys