TDS not changing much after DI resin

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GSnake

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hi,

had a rodi buddie 50 gpd, worked well for 4 years. switched to 4 stage 100gpd aquatic life classic, installed it today.

getting 9 tds from 140 tap water out of RO membrane,
and 6 after DI.

ran the ro membrane for a few hours with prefilters (3hours?), and ran it with di for 1hr with the results above

Am i missing something in the Di installation? or does the di need a break in period too? its just the plastic housing with an oring for the canister. seems simple enough
 
I had the same issue, check to see if the DI resin cartridge is seated well or damaged. Peel off the top white piece and see if it looks flush or warped.

Mine came warped from the factory.
 
Did you pack the DI resin tight with no spaces? No need to flush DI resin, just a waste of resin and water. RO membrane is working well, the problem is the DI. Do you have the water flowing proper direction? Try a 3 stage DI resin setup, Cation-Anion and mixed bed. I have gotten better results after going with this setup.
 
What are you using to test your TDS?

In-line meters are not very accurate based on my experience. Get a good hand-held one to compare the tds.
 
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mine looks the same!
not sure if it was me who caused it though, or it was like that from factory. my lfs offered a replacement cartridge for me.
aquatic life support suggested i turn the bottom of cartridge half turn to one full turn looser to increase height of the DI cartridge, so it fits better. I did this and got 0 tds. even though im getting 0 tds i was thinking if the damage is causing the TDS to become diluted so, its actually <1 or something rather than a true 0 . [clearing this up at the moment. ]

i use a tds pen, not an inline right now, but considering adding an inline ..

ya its in the proper direction and its a factory new cartridge with DI, i didn't fill it myself yet.

my psi from the 50 gpd buddy is 105~ and with the 4 stage 100gpd its 85~
 
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You may have an issue with the RO membrane also. You are around 94% rejection which is just below the normal bare minimum from a membrane. I run 4 to 5 after my membrane with my tap going as high as 450.
 
You may have an issue with the RO membrane also. You are around 94% rejection which is just below the normal bare minimum from a membrane. I run 4 to 5 after my membrane with my tap going as high as 450.
Im getting 6 now from the membrane, maybe its still just new.
 
Unfortunately, this has happened to me before and I can say definitively it was my fault... you have to be really careful when you are tightening the DI canister housing because if the DI cartridge is not vertically aligned with the housing then the collar on the inside of the top of the canister that seats onto the gasket on the DI cartridge will be misaligned and deform/cut into the DI cartridge just like your picture.

You should look up inside of the DI canister housing (the female threaded part) to make sure the housing collar isn't damaged as well... unfortunately in my case it was. I was able to manually work the plastic back to form enough to work for a while...

Good luck!
 

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