Ruined a new DI cartridge

[StokesReefer]

I think I just ruined my new DI cartridge in a strange mistake. I made 10 gallons of water with my brand new Spectrapure RO/DI unit after installing it today. Because I still had a long product water line, it was laying in the bottom of the bucket as I filled it. When the second bucket was half full, I dumped the salt in both buckets to start mixing. I shut off the water when the second bucket was full. Like 4 hours later, I wanted to test the pressure late at night. I turned the water back on and happened to look at the TDS meter showing the product water line (which had been zero after the setup was completed). It was somewhere above 100, then bouncing around at 30-40ish for a long time. It settled eventually at 2, which is the same as what was coming out of the RO membrane. So I think that in the 4 hours that the water was shut off and the product line was sitting in a bucket of salt water, the salt crept up the line and into my DI cartridge, exhausting it completely :/ It’s a non-colour changing resin, so all I have to go on is the TDS meter. Does this explanation make sense?

 

[Moscar]

I think I just ruined my new DI cartridge in a strange mistake. I made 10 gallons of water with my brand new Spectrapure RO/DI unit after installing it today. Because I still had a long product water line, it was laying in the bottom of the bucket as I filled it. When the second bucket was half full, I dumped the salt in both buckets to start mixing. I shut off the water when the second bucket was full. Like 4 hours later, I wanted to test the pressure late at night. I turned the water back on and happened to look at the TDS meter showing the product water line (which had been zero after the setup was completed). It was somewhere above 100, then bouncing around at 30-40ish for a long time. It settled eventually at 2, which is the same as what was coming out of the RO membrane. So I think that in the 4 hours that the water was shut off and the product line was sitting in a bucket of salt water, the salt crept up the line and into my DI cartridge, exhausting it completely :/ It’s a non-colour changing resin, so all I have to go on is the TDS meter. Does this explanation make sense?

Hi, You just had TDS creep through your membrane -- it's normal! One way to help your resin and membrane out is to open up the flush valve for a short time before each use.
A float valve will save you a big messsy overflow. I use a float valve backed up with an Auto Aqua sensor/ valve.

So, flush your membrane, and have fun.

 

[StokesReefer]

TDS creep shows up at the output of the RO membrane, not the output of the DI stage. And the DI output stayed at 2 ppm for like an hour.

 

[KStatefan]

If the line from your DI down to your mixed salt water the salt would start to move up that to your DI if there was not a valve there. With sea water being 30,000+ TDS it would not take much to exhaust your resin.


Flushing the membrane does not remove TDS creep. A DI bypass valve is what you use to remove TDS creep.

 

[StokesReefer]

If the line from your DI down to your mixed salt water the salt would start to move up that to your DI if there was not a valve there. With sea water being 30,000+ TDS it would not take much to exhaust your resin.

Thanks, this is what I suspected.

 

[StokesReefer]

Ok so happy update.... I just did the water change that I was preparing for, and after I took out the buckets I found a large rubber washer on the floor... Sure enough, it was the washer from the top of the DI resin cartridge. I replaced it, and voila - back to zero TDS output. I guess that when I first saw the high TDS coming out of the DI stage, I took off the DI canister to dump any water out of it and replaced it. I guess the washer fell off and then the water was bypassing the DI resin. In summary it seems the salt creep up the product line was real, but thankfully it didn’t exhaust my whole DI cartridge.