RO Unit Questions

Discussion in 'Test Kits, Controllers, Reactors and Dosers' started by Galibore, 1 Dec 2008.

  1. Galibore

    Galibore Retired Moderator

    Joined:
    6 May 2007
    Posts:
    2,829
    Likes Received:
    19
    Location:
    Germiston
    Hi Guys,

    I was wondering, for how long at a time do you guys flush your RO units for and how often.

    What normally goes first on a 4 stage? In other words, what should I look at replacing first?

    My TDS reading has always been zero. Now it reads 2. My unit is probably about 10 months old and I haven't replaced any of the inserts yet. It's got the sediment filter, carbon block, RO membrane and DI resin.
     
  2. AdS Guest




    to hide all adverts.
  3. Mike

    Mike Retired Moderator

    Joined:
    12 May 2007
    Posts:
    7,859
    Likes Received:
    30
    Location:
    the Motherland
    Change the DI resin, i find that is usually first to go, and by the readings it looks like it has gone, how long all the filters last is down to how good the water is to start with, it the TDS input is high it will wear down the filters quicker, but i'd look to be replacing all the filters annually anyway.
     
  4. lanzo

    lanzo Sponsor

    Joined:
    10 Sep 2007
    Posts:
    9,396
    Likes Received:
    26
    Location:
    Centurion
    i change my di resin when it turns yellow, and then i change my sediment filter when readings go above 0 and if it stays at 2 change the carbon( the membrane is done last)

    you got a new tank or what?
     
  5. Obi-Wan

    Obi-Wan

    Joined:
    15 May 2007
    Posts:
    318
    Likes Received:
    23
    Location:
    Cape Town 7442
    RO DI prefilter maintenance interval

    Good to see you're around !

    Use below as a working guide.
    I have used RO, in PE, CT, JNB.

    Flush before EACH use. About 5minutes.
    Especially if RO used less than 2/week.


    Change DI as soon as it's exhausted according to colour-indicator .
    IF you DON'T have colour indicator resin, then testing is in order.
    DI resin volume treatment capacity is lowest, therefore gets used up quickest.

    THEN sediment
    THEN Carbon Block Resin
    LAST 2 ARE BEST CHANGED SIMULTANEOUSLY.

    QUICK TIP!!
    Flush membrane.
    Disconnect DI
    test TDS of RO, before DI
    Then you have idea of WHAT level tds is removed by your DI, as is.

    Workout Tapwater RAW tds
    KNOW that good RO removes min 90-95% of THAT.
    DI polishes remainder down to 95-99% IF REQUIRED

    eg)
    My CT tap is 60ppm tds
    RO yields 2-6ppm [Tested: NO phosphate, nitrate, silicate]
    DI makes it 0-1ppm

    I am perfectly happy with using my RO, and don't bother with DI.
    BUT, it's connected, ready to be charged and brought online within minutes.

    All depends on how bad raw-feed water is ....

    I use it as long as under 10ppm, replace ALL prefilters every 2-3months or sooner. With regular, weekly testing to maintain margin of safety

    According to needs, I produce 500 - 3000L a week .


    You are FAR from membrane replacement

    Hope this helps abit, at least.



     
  6. Darryl

    Darryl

    Joined:
    20 Nov 2008
    Posts:
    129
    Likes Received:
    1
    Location:
    Hillcrest
    It's so easy to to check the state of your sediment filter. I replace mine as soon as it gets a shade of brown.
     
  7. crispin

    crispin

    Joined:
    22 Jan 2008
    Posts:
    12,223
    Likes Received:
    160
    Location:
    Lilliehammer, Norway
    out of intrest, with hard or calcium rich water, would a RO unit strip the calcium out as well?
     
  8. mike Bushie

    mike Bushie

    Joined:
    14 Apr 2008
    Posts:
    630
    Likes Received:
    1
    Location:
    johannesburg
    might be a stupid question but how to you "Flush membrane"
    and how much is a tds meter and where do you get them?
     
  9. Warr7207

    Warr7207

    Joined:
    28 Dec 2007
    Posts:
    12,781
    Likes Received:
    31
    Location:
    JHB
    If you have it permanently connected, not really an issue. Flushing the membrane is basically running water through the unit for 30 minutes or so.

    Get from LFS or sponsors
     
  10. mike Bushie

    mike Bushie

    Joined:
    14 Apr 2008
    Posts:
    630
    Likes Received:
    1
    Location:
    johannesburg
    i have it permanently connected and i use it 2 a week. so should i not worry about it.
    how much do they normally go for?
     
  11. Warr7207

    Warr7207

    Joined:
    28 Dec 2007
    Posts:
    12,781
    Likes Received:
    31
    Location:
    JHB
    I have been running my RO for 12 months now at Zero TDS and have not had to replace membrane or filters.

    Replacement is dependant on usage and the quality of the tap water.

    That is why the TDS meter is important for monitoring purposes
     
  12. Tobes

    Tobes Retired Moderator

    Joined:
    30 Nov 2007
    Posts:
    9,482
    Likes Received:
    118
    Location:
    A Beautiful place!
    Bought mine for R300 at Eco-Aquatics, that was over a year ago, might be double now :p
     
  13. Tobes

    Tobes Retired Moderator

    Joined:
    30 Nov 2007
    Posts:
    9,482
    Likes Received:
    118
    Location:
    A Beautiful place!
    Mine as well, been running 13 months and still tests 0. Tested my tap water and TDS = 40 :slayer:
     
  14. dallasg

    dallasg Moderator MASA Contributor

    Joined:
    14 Dec 2008
    Posts:
    16,771
    Likes Received:
    582
    Location:
    Sandton
    i just bought my RO unit now, hopefully get it on monday/tuesday
     
  15. Reef Maniac

    Reef Maniac MASA Contributor

    Joined:
    15 May 2007
    Posts:
    2,899
    Likes Received:
    112
    Location:
    Bloemfontein
    Good advice there from Obi-Wan (Hi Obi-Wan, long time to hear :wave2:)

    Most important variable is, of course, the quality of the input water.

    Here in Bloemfontein our water is VERY dirty (sediment/mud), and I need to change my first sediment pre-filter (I use 5 micron) every 2 months or so (sometimes even more frequent...)

    The carbon block pre-filter's main purpose is to remove chlorine (added by the municipality to "sterilize" the water), as this attack the actual RO membrane. Depending on how diligent your municipal water treatment people are, you might need to replace this pre-filter as often as every 6 months, or as long as once every year. As the carbon block pre-filter is substantially cheaper than the actual RO membrane, I would advise to rather be safe than sorry, and replace it every 6 months.

    As a point of interest, because of Bloem's atrocious water quality, I have 4 pre-filters ahead of the RO membrane: from the municipal water supply side there is firstly the 5 micron sediment filter, then a GAC (granular activated carbon, same as we use in our aquaria), then the carbon block, and lastly a 1 micron sediment filter. In general, I replace the first two every 2 months, and the last two every 6 months.

    Hennie
     
  16. dallasg

    dallasg Moderator MASA Contributor

    Joined:
    14 Dec 2008
    Posts:
    16,771
    Likes Received:
    582
    Location:
    Sandton
    come to sandton, great water ahaha
     
  17. Reef Maniac

    Reef Maniac MASA Contributor

    Joined:
    15 May 2007
    Posts:
    2,899
    Likes Received:
    112
    Location:
    Bloemfontein
    Ja, I suppose that's the advantage of private enterprise - someone is obviously removing the mud from the water to use it to decorate your shiny 4x4's :whistling: :whistling:
     
  18. dallasg

    dallasg Moderator MASA Contributor

    Joined:
    14 Dec 2008
    Posts:
    16,771
    Likes Received:
    582
    Location:
    Sandton
    touche' , but it aint private, its our wonderful rand water board...

    if i may ask hennie, your profession? engineering of some sort? coz ur setups are wonderful, if i could afford the shipping your 1m cube would look good in the center of my lounge
     
  19. Reef Maniac

    Reef Maniac MASA Contributor

    Joined:
    15 May 2007
    Posts:
    2,899
    Likes Received:
    112
    Location:
    Bloemfontein
    Yup, you guessed it :thumbup:

    Perhaps you've got me confused with someone else - my tank is a 1.8 x 0.7 x 0.7, and not a cube (wish I had space for a decent size cube, though...)

    Hennie
     
  20. dallasg

    dallasg Moderator MASA Contributor

    Joined:
    14 Dec 2008
    Posts:
    16,771
    Likes Received:
    582
    Location:
    Sandton
    my bad i did...
    nice tank, but a bitch to ship unless stripped
     
  21. dallasg

    dallasg Moderator MASA Contributor

    Joined:
    14 Dec 2008
    Posts:
    16,771
    Likes Received:
    582
    Location:
    Sandton
    a quick Q, i have a waterboy RO unit, reefmaster evolution, should the waste produce more water than the RO outlet? also isnt the waste water good for anything seems to be a "waste" of water.. thanks
     
Recent Posts

Loading...
Similar Threads - Unit Questions Forum Date
RO unit questions. Beginner Discussions 3 May 2011
questions on RO unit The Waterboy 9 Feb 2011
[wtd] RO unit wanted Wanted 26 Nov 2016
[wtd] Broken or unused led unit Wanted 21 Nov 2016
[wtd] R.O. Unit Wanted 29 Oct 2016
[wtd] ATI 6 or 8 bulb 39w unit Wanted 17 Oct 2016
RO unit waste water used for freshwater aquarium? General Discussions and Advice 7 Oct 2016