TDS reading 3pps

Discussion in 'Test Kits, Controllers, Reactors and Dosers' started by Difficult marine, 15 May 2011.

  1. Difficult marine

    Difficult marine

    Joined:
    18 May 2009
    Posts:
    241
    Likes Received:
    1
    Location:
    cape town
    Hi Guy
    I have RO unit from Waterboy when the reading was 6ppm. I change all filter media but the reading only come down to 3ppm,can't come down to 0ppm.When the unit new reading is 0ppm. Do you have any experience like that? or i did something wrong. The tap water reading is 38ppm.
    regards
     
  2. AdS Guest




    to hide all adverts.
  3. viper357

    viper357 Admin MASA Contributor

    Joined:
    4 May 2007
    Posts:
    27,982
    Likes Received:
    777
    Have you got DI resin? If so did you replace that? Also, have you given the new filters a good flush to get rid of all the carbon dust etc.(without the membrane plugged in)?
     
  4. Tony

    Tony

    Joined:
    23 Aug 2008
    Posts:
    4,093
    Likes Received:
    68
    Location:
    Honeydew, Johannesburg
    What's the TDS of your raw tap water?
     
  5. Difficult marine

    Difficult marine Thread Starter

    Joined:
    18 May 2009
    Posts:
    241
    Likes Received:
    1
    Location:
    cape town
    i did flush but didn't unplugged the membrane (the manual only said regular flush,didn't said unplugged membrane) will try.

    i did have DI resin but i didn't replace,they only make the water more soft. i can try unplugged , don't use anymore.
     
  6. viper357

    viper357 Admin MASA Contributor

    Joined:
    4 May 2007
    Posts:
    27,982
    Likes Received:
    777
    You must replace your DI resin, this polishes the water thereby bringing down your TDS reading to 0, also I have found my DI resin is exhausted well before the other filters so it gets replaced twice before I replace the other filters.
     
  7. Difficult marine

    Difficult marine Thread Starter

    Joined:
    18 May 2009
    Posts:
    241
    Likes Received:
    1
    Location:
    cape town
    my tap is 38ppm
     
  8. Difficult marine

    Difficult marine Thread Starter

    Joined:
    18 May 2009
    Posts:
    241
    Likes Received:
    1
    Location:
    cape town
    First i will try unplugged and see. If don't work i will order the DI resin form Waterboy.
    thanks
     
  9. Suhayl

    Suhayl

    Joined:
    24 Sep 2007
    Posts:
    1,229
    Likes Received:
    18
    You sure you have the right tds readings? A tds of 38 very good for tap water and one would need the di resun to get 0 readings. How old is the membrane as that the hearst of the ro unit?
     
  10. flappy

    flappy

    Joined:
    18 Jul 2007
    Posts:
    1,273
    Likes Received:
    52
    Location:
    Cape Town
    A TDS of 3 is great,not a noticiable diff in your tank beween 0 and 3.
     
  11. Reef Maniac

    Reef Maniac MASA Contributor

    Joined:
    15 May 2007
    Posts:
    2,899
    Likes Received:
    112
    Location:
    Bloemfontein
    That sounds about right - the "filter media" does not really remove TDS, it only pre-filters the media to prevent the RO membrane from becoming blocked or damaged - the RO MEMBRANE is the actual filter that removes TDS, and I take it that you did not replace the membrane.

    A good, fresh RO membrane will usually not give you a zero TDS reading either - around 2ppm - 3 ppm is normal. That last 2-3 ppm of TDS is only removed by the DI resins, but as flappy commented above, a TDS of 3 ppm is still perfectly OK.

    Hennie
     
  12. IMarine

    IMarine

    Joined:
    20 Oct 2007
    Posts:
    1,512
    Likes Received:
    16
    Location:
    walmer estate capetown
    ro

    excellent advice there
     
  13. Manic

    Manic Moderator

    Joined:
    12 Mar 2009
    Posts:
    3,313
    Likes Received:
    58
    Location:
    Johannesburg, Edenvale
    RO membranes remove around 99% of the TDS so it is vital to have DI resin to remove the remaining TDS. Also cation resin doesn't remove all the TDS (Gold coloured resin) the blue colur changing resin (anion) works the best IMO
     
  14. Difficult marine

    Difficult marine Thread Starter

    Joined:
    18 May 2009
    Posts:
    241
    Likes Received:
    1
    Location:
    cape town
    What is the reading for the time change membranes any suggestion?
     
  15. TheWaterboy

    TheWaterboy Sponsor

    Joined:
    6 May 2007
    Posts:
    2,117
    Likes Received:
    79
    Location:
    Durban
    colour has nothing to do with it being a anion or cation..........
    the blue resin is a indicator resin that changes colour when exhausted.

    they both mix bed resins that are made of both anions and cations......
    however the blue indicator resin is best s there are alot of terrible standard gold brown resins.....

    the blue resin is generally fron good manufacturers , i good supplier is extremely difficult to find.
    we have 2 suppliers that we use............

    15 + before it reches the resin
     
Recent Posts

Loading...
Similar Threads - reading 3pps Forum Date
TDS Reading of RO Water Water Parameters and Additives 17 Nov 2016
RO water and TDS reading Water Parameters and Additives 25 Apr 2016
Salinity Reading @ 0 Water Parameters and Additives 30 Aug 2015
Salt readings Beginner Discussions 24 Aug 2015
RO filter TDS readings Water Parameters and Additives 29 May 2015
New, broke & reading way to much. New Members 29 Mar 2015
Low readings and dosing questions Beginner Discussions 8 Mar 2014