Very frustrated with my RODI. Do I need 1 micron filters?
 

I was gifted a new rodi unit but it came with 5 micron filters. I did not think it would matter and added a di canister to it. I bought fresh new di resin yesterday and it was pumping out 0 tds. Today it will not go below 4 tds! I just spent the money and time replacing the membrane, filters, and di, and it still will not go below 4. My water coming in is at 188.

Any advice? :hmm2:

The 5 micron is fine, 1 micron changes nothing.

The actual ro membrane determines what is fed to the DI.

You may want to clear the system for a minute before allowing water into the DI stage. TDS creep is real

Also it helps us and you if you know what the TDS is leaving membrane before DI

It also helps to have DI cartridge up and down not laying on its side.

Outy is correct. The sediment and carbon filters do nothing to change the tds of the water. Their only purpose is to protect the RO membrane from large particles and chemicals. That said, I only use 1 micron or .5 micron prefilters, but only to better protect the RO membrane. Knowing your tds after the ro but before the di will help determine if there is an issue with the RO membrane. If it is working correctly your 188 water should be between 3 and 9 if your RO membrane is working to spec. Even at a tds of 9, your di should produce around 500 gallons of 0 tds water before it starts going up.

Well water with high CO2?

But yes.. lots of questions for you and some pictures of your setup just to make sure nothing is hooked up wrong,etc..
You sure you are getting the water after the DI stage?
Is it a cheap horizontal DI stage?

Thank you so much for everyones help. After looking at my system, my di was running Before my membrane. I switched the inline tds meter to read after the membrane and after the di stage. Right now it states that I have 12 tds after the membrane and 4 tds after the di stage.

DI stage plumbed before RO? yep thats certainly the eason for your problems..

Now your DI resin is just shot from that abuse..
Replace it and all should be good again..

Do you know the PSI at the membrane? Id also check the TDS before it goes into the DI resin.

he did its 12

The size of the pores in the sediment filter is important - you'll want the pore size in the carbon block to be about the same or larger than the pore size on the sediment filter - otherwise your carbon block will trap sediment.

Russ

Yup, it will reduce life of carbon blocks if the prefilters aren't rated the same or better as the carbon.

Your PSI incoming needs to be about 60 PSI min! That will help lower your TDS.

Yeah if you use up all your resin like that you reach breakthrough and worse, the filter will start actually releasing TDS back into the water. Replace and then try again!

Filmtec residential membranes will perform reasonably down to about 40 psi. They are factory tested at 50 psi.
Higher pressure, within limits, is better.

Russ