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dweber618
12/05/2015, 08:22 AM
I just recently purchased a TDS to check the output of my RO/DI. I have the IN reading right after my pre filters and entering the membrane. My TDS is around 200ppm. The OUT reading is directly after the membrane (but before my DI) and the reading is 8ppm. I just replaced all the cartridges, and my DI.

My question is - how much will the DI reduce TDS? Do I need a new membrane? Thanks for any tips!

dkeller_nc
12/05/2015, 08:56 AM
If your DI cannister is properly packed, and the resin's not exhausted, it will reduce the TDS to zero. Your reject ratio for your RO is 96%. That's not absolutely stellar, but depending on what's in your source water, your incoming water pressure, and the membrane's age, it doesn't suck, either.

C.Eymann
12/05/2015, 10:00 AM
I just recently purchased a TDS to check the output of my RO/DI. I have the IN reading right after my pre filters and entering the membrane. My TDS is around 200ppm. The OUT reading is directly after the membrane (but before my DI) and the reading is 8ppm. I just replaced all the cartridges, and my DI.

My question is - how much will the DI reduce TDS? Do I need a new membrane? Thanks for any tips!

I would place the in sensor right after the membrane and the out sensor on product water (after DI)

Putting one before the membrane doesn't tell you much. Just my .02

dweber618
12/05/2015, 10:36 AM
Thanks for the feedback! Will fix it so I can move the sensor and seal up the other connection.