Replaced RO membrane and still get higher TDS output?

[Phyber]

I have a BRS 4 stage RODI, and I recently ordered replacement filters for it as my others hadn't ever been swapped out. I got a new 1 micron sediment, 1 micron carbon, a DI mixed bed refill, and a DOW 75 gpd membrane.

I have well water that comes in at 60 TDS at the tap for my RODI, and I run an AquaTech booster pump from 75-80 psi, connected after the prefilters and before the RO membrane.

I installed the new filters, sans DI resin cartridge, and let it run off about 5 gallons of water, or an hour run time. I saw the TDS of the RO output hover around 1-2 TDS.

That was the last I ever saw of that. The next weekend I put my DI resin in and began making product water, and my RO output will not go below 4 TDS. Tried flushing in different intervals, won't budge.

Any idea what's going on? My original RO was putting out 5 TDS which is why I replaced it!

 

[theMeat]

Did you rinse cartridges before install.
What’s your waste/ product ratio?

 

[Phyber]

Did you rinse cartridges before install.
What’s your waste/ product ratio?

Unfortunately I did not rinse anything, and didn't realize it until after. However, if they did junk up the RO, how did I ever see 1-2 TDS?

Not sure on the ratio, I just have shoved the waste water hose down the drain. I know I'm making water faster now with this pump than before on just house pressure.

 

[robbyg]

You might be chasing your tail trying to read between 1-4 TDS on the RO output. The typical meter is just not that accurate.

 

[theMeat]

Hand held tds meter good to have on hand when diagnosing.
Di resin will take down tds until it is exhausted.

 

[Phyber]

Hand held tds meter good to have on hand when diagnosing.
Di resin will take down tds until it is exhausted.

Hi!

Yes, the DI was polishing the final water down to 0 TDS, but I was looking to save resin life as I know I have higher co2 anyway. The difference between 1-2 and 4-5 TDS in RO output wouldn't help with life

 

[theMeat]

What’s your tds in and out of membrane ?

 

[Phyber]

What’s your tds in and out of membrane ?

60 TDS in, 4 TDS out.

The 4 TDS goes into DI and comes out 0 TDS, however I only got about 50 gallons of life out of a mixed bed DI cartridge.

 

[theMeat]

60 TDS in, 4 TDS out.

The 4 TDS goes into DI and comes out 0 TDS, however I only got about 50 gallons of life out of a mixed bed DI cartridge.

Should get plenty out of di resin only asked to remove 4 tds. Something’s up with resin

 

[Phyber]

Should get plenty out of di resin only asked to remove 4 tds. Something’s up with resin

I don't have a DI flush setup yet, and well water has high co2, so those are against me...

But my concern is with the RO...again, my 10 year old original filter was putting out 5 TDS. This brand new one is putting out 4...

 

[theMeat]

Not aware that co2 will exhaust resin any faster than anything else. Maybe some of the rodi experts will pop in. Know the membrane isn’t completely effective at removing co2 but with resin only taking out 4ppm would think it would last plenty.
Easy enough to remove c02