Can't get ro-di water to zero

[Joewestwood]

Hey friends,

Just changed everything out of my 4 stage brs ro-di with new filters and can't get the tds below 4. I've made about 30 gallons and have packed the di resin super tight.

Thoughts?

 

[SeaSickness]

You may want to consider a booster pump. It improves membrane rejection performance.

 

[Uncle99]

Me either, 3-4ppm, best I can do.
But this can just be testing error, I doubt anything 5 and below is of any real concern.
Been making 3-4ppm RODI for 30 years, never caused any problem whatsoever.

 

[Topreefer92]

So I ran into this issue and did the same thing you did. My random and totally not scientific fix was, I unscrewed the di resin canister and the screwed it back on, then in less than a minute the tds went to zero.

 

[Cory]

I get 0 to 1 tds from 150 tds tap water with a spectrapure select plus membrane. I use a booater pump which gets the pressure to about 80psi. I dont use deion as 1 tds is not a concern.

 

[krash7172]

When my 5 stage is fresh including chloramine block I still have tested up to 4 ppm. My tap is 350 ppm and I have chloramine so I'm happy.

 

[Greg P]

Take the membrane out, check the seals, re-seat it 'firmly', then try again.
Could be bypassing