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Featured ro unit tds?

Discussion in 'Help and Advice' started by warby, Nov 10, 2014.

  1. warby

    warby Registered

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    Ran off my top up water for this week (25l) my incoming tds was 44 and my outgoing tds was 4. Which isn't the best.....but the week before when doing enough water for 2 weeks changes (80l ish) incoming was 106 (which it what it normally is give or take a few ppm) and 0 out. I don't have a tds pen I just rely on the dual tds meter built into the Ro unit. I can borrow a tds pen from my lfs to check my water but I'm.wondering of anyone can come up with an explanation for the big differences within 1 week....i flush my unit for a few hours per month to clear it out......is it time to swap out the filters? How often do the inline tds units need calibrating? Had the unit 6months ish and iv not done it.....also not changed the filters. But don't want to spend on filters/membrane if I don't have to
    [MENTION=11655]LittleOcean[/MENTION] I think iv may have heard your name once or twice when it comes to Ro units hahaha :)
     
  2. diver 807

    diver 807 Registered

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    have you got a di resin pod.
     
  3. warby

    warby Registered

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    yeah sorry forgot that bit, its got 5 or 10 micron sediment (cant remember which), carbon membrane then di (if iv got the order right)
     
  4. McPikie

    McPikie Registered

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    Sure your DI is packed tight enough
     
  5. warby

    warby Registered

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    yep, iv changed nothing its been fine for the last 6 months and now a dodgy reading......think ill call to lfs tomorrow and borrow there tds pen and see what my tap water is as 44 seems really clean to me and 4 going out when it was 0 dosent make sence.....ill see what tds pen says
     
  6. McPikie

    McPikie Registered

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    Resin has probably ran out then
     
  7. LittleOcean

    LittleOcean Registered

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    Tds can go through the roof of you had water works near by, it only takes a bit of sediment to be disturbed which can block your sediment filter and possibly ruin your carbon too.. If left this can them effect the membrane ...

    You have very high Tds post menbrane , do you know what the input Tds is to the membrane and the out ? (Before resin )

    But yes your resin sounds like it's exhausted
     
  8. warby

    warby Registered

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    Erm.....in a word no iv just got the inline tds meter before the filters then the other one after it comes out of the di pod. It just seems strange how for the last 6months the incoming had always been about 106 but this week it was way down at 44ppm. But the out going was 4ppm. I'll call in at my lfs later today and either buy a tds pen or borrow there's.
    The 106 pom figure is from before it entered any filters (I bought the unit like this) is it in the wrong place? Sorry if I'm not being clear don't really know that much about the Ro units all I do is connect it to tap and switch on look at tds in and tds out lol. This is the first issue iv had.

    What are the chances of 44ppm tds going in to be right that seems really "clean" to me. And no there hasn't been any water works going on that I know of :)

    Thanks so far toby :)
     
  9. NeilBPrater

    NeilBPrater Registered

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    The other possibilty is that your meter needs re-calibrating.
     
  10. LittleOcean

    LittleOcean Registered

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    with input at 106 you need you pre DI resin to be around the 6 mark, so 44 is awful... good news is that's really low input tds..

    filters should be,, sediment > carbon > membrane > DI resin

    when you flush it's a good idea to by pass the resin or this will deplete your resin quicker... whenever you leave your membrane tds creep occurs which means the good side of the membrane gets tds of equal amount to the bad side... hence when you flush you always have a tds reading at the start..

    if after a 2 hour flush and 20 mins running the 44 tds doesn't come down I would change the membrane and the pre-filters (if old) oh and of course the resin..

    hth
     
  11. warby

    warby Registered

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    I think I may have confused you toby.....outside tap>ro tubing>inlet tds meter>sediment>carbon>membrane>di pod> outgoing tds meter.

    So the inlet tds meter normally shows about 106ppm and the outgoing tds normally 0ppm. But this week incoming tds 44ppm outgoing tds 4ppm. It could just be it wants calibrating.

    Iv got some spare di resin that I was given with the unit so if they did want changing id need sediment carbon and membrane.
     
  12. LittleOcean

    LittleOcean Registered

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    ah right, yeh that's odd, but try to record the tds before the resin too, I normally calibrate my meter when I know I have fresh resin and I'm certain it's 0 without the use of the meter..

    it might just be your resin is depleted or the water has found a path around the resin
     
  13. warby

    warby Registered

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    Ok ill set the unit up again tonight and test before and after the resin and also before and after the pre filters. Then post back here and go from there......sorry about confusing you matey....my explanation wasn't the best reading it again now haha :)
     
  14. warby

    warby Registered

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    Didn't get time to set unit up but I got myself a tds pen lfs calibrated it for me and I checked it. My tap water really is 44ppm but the Ro water iv done is 0ppm so it looks like my dual tds meter needs calibrating panic over haha....
     
  15. NeilBPrater

    NeilBPrater Registered

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    I refer to my previous post.:-d
     
  16. warby

    warby Registered

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    Smart **** :whistling: Haha :)
     
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