Upgrading to Spectrapure RO membrane...need help

Discussion in 'SpectraPure' started by Akool, Jun 2, 2012.

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  1. Akool

    Akool Astrea Snail

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    I have a 100gpd BRS RODI and recently my water production has greatly slowed down. I have 55psi coming in and have changed all filters and DI. Im guessing its time for a new membrane...I would like to use a spectrapure, so which would be the best membrane to go to( 75, 90, 100 gpd)? I hear the 100 has a lower rejection rate and if i change from 100gpd what else will i need?

    Thanks!
     
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  3. BuckeyeFieldSupply

    BuckeyeFieldSupply Spanish Shawl Nudibranch

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    Before you go to the expense of replacing your membrane, why not check if your current membrane is still good?

    1. Measure the output in gallons per day (you can measure it cups per minute or however you'd like and convert it to gpd). Record your water pressure and water temperature, and input that information to the calculator you can reach from our homepage. See if it is producing water as fast as it should given your temperature and pressure. One sign of a membrane gone bad is slowed production.

    2. Calculate the rejection rate after measuring the tapwater TDS and the RO water (not DI) TDS. One sign of a membrane gone bad is a poor rejection rate.

    Russ
     
  4. Akool

    Akool Astrea Snail

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    I will try that when i get home tomorrow but I'm not sure what else it could be. Changed out the filters and di resin and it is producing lots of waste water and the good water is barely dripping. The current membrane is 3 years old
     
  5. BuckeyeFieldSupply

    BuckeyeFieldSupply Spanish Shawl Nudibranch

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    Do you have a pressure gauge on your system?

    Do you have a flush valve?
     
  6. Akool

    Akool Astrea Snail

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    Yes pressure is almost 55. I do have a flush valve and tried flushing for 30 min
     
  7. BuckeyeFieldSupply

    BuckeyeFieldSupply Spanish Shawl Nudibranch

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    Your 55 psi is fine.

    Make sure your flush valve is closed.
     
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  9. Akool

    Akool Astrea Snail

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    It took 4 hours and 30 gallons of waste water to make 5 of good water
     
  10. BuckeyeFieldSupply

    BuckeyeFieldSupply Spanish Shawl Nudibranch

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    So your waste:permeate ratio is 6:1 (should be ~4:1)

    And you're making 30 gpd.
     
  11. BuckeyeFieldSupply

    BuckeyeFieldSupply Spanish Shawl Nudibranch

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    And you are certain you have 55psi that reaches the membrane?

    What is the tap water TDS?
    What is the RO water (not DI water) TDS?
     
  12. Akool

    Akool Astrea Snail

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    It is showing 55psi on the gauge and will drop down to 30 when im flushing, is that normal? not sure of the tap water tds, I have a inline dual tds meter and it shows 12 before the DI and 0 after.