RO/DI Question - TDS meter reading 5 ppm after RO Membrane and 3 ppm after DI Resin Chamber

Discussion in 'Equipment' started by 177ike, Jan 23, 2010.

  1. 177ike

    177ike Guest

    Hello everyone,

    I'm trying to battle my newly cycling tank and a GHA outcropping going on right now.. I'm also trying to think of any other possible input/contributors to the problem as the tank cycles. I've had my BRS Five Stage unit running for close to a year with the TDS meter showing 3 ppm after RO Membrane and always 000 ppm after DI Resin Chamber. However, I recently noticed my TDS after DI Resin showing 2 ppm and decided it was time to swap out all filters and resin. The only filter not changed was the RO Membrane. I've made over 40 gallons using the newly changed filters/resin but what's troubling is that I'm now reading 5 ppm after membrane and 5 ppm after resin chamber. I don't understand why my TDS readings are higher than prior to changing everything. Could the TDS meter need calibration? Any thoughts on this?


  2. revo

    revo Guest

    i would check the meter first. I have the vertex RO/DI and the TDS meter bounces between 0-30. Luckily i have a Hannah portable and an analog tds meter to compare. my RO membrane went bad too in 9months but MD warrantied it and sent me additional filters. What i think i did wrong was let the membrane dry out in between uses.

    Can it be your live rock?

    Good Luck.
  3. GreshamH

    GreshamH Guest

    I highly doubt your GHA is due to a 5ppm TDS coming out of your RODI but I still would try to figure out why it's doing that.
  4. 177ike

    177ike Guest

    Just figured it out... I put the DI Resin cartridge in upside down when I switched it out!!! Good thing I noticed the "This Side Up" on the cartridge from BRS when I installed the GFO Reactor cartridge.

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