Strange TDS levels

Nico2176 · Jul 4, 2022

I recently changed all the filters on my ro/di system, and after flushing everything out I tested 4 tds coming out of the ro membrane and 4 tds exiting from the di resin. All of these filters were purchased new, is it possible that the di resin is faulty? The water coming into the system was tested at 285 tds. For clarification these values are all in ppm. Most of the time placing these filters are easy, but this has been a real headache chasing 0 tds. Any help would be greatly appreciated.

Biglew11 · Jul 4, 2022

Did you replace the di resin or is it still the same. was this a refillable cartridge that you filled, or was it a purchased cartridge? If you refilled the cartridge make sure it is packed tightly. I use 3 di resins and when replacing the anion resin I will get high tds out of it for about 15-30 minutes.

Lonely reefer's · Jul 4, 2022

Check the DI cartridge probably installed backward, I done it before

Nico2176 · Jul 4, 2022

Biglew11 said:
Did you replace the di resin or is it still the same. was this a refillable cartridge that you filled, or was it a purchased cartridge? If you refilled the cartridge make sure it is packed tightly. I use 3 di resins and when replacing the anion resin I will get high tds out of it for about 15-30 minutes.

It was a purchased cartridge I got off of Amazon. Specifically the Aquatic life 3 pack (micron filter, carbon block, and di resin). I want to confirm that the di resin should remove the remaining tds from the membrane, so in this case the 4 tds from my membrane would under normal circumstances be removed right? I can try letting it run, but it’s strange I’ve never had to let it run before. I use to just put the filters in and immediately get 0 tds.

Nico2176 · Jul 4, 2022

zoasaholic said:
Check the DI cartridge probably installed backward, I done it before

Just checked and it was placed correctly, one thing I did do was I opened the package and left it sitting for about an hour because I had to flush the membrane. I bought a new membrane. Would letting the do resin exposed to air make it go bad?