Lifespan of membranes

Discussion in 'Water Fed Pole Cleaning' started by Daftoldgit, Jun 17, 2014.

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  1. Daftoldgit

    Daftoldgit Member
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    Hi, how long do you find your membranes last?
    I have to change mine at least once, sometimes twice, a year. The manufacturers all seem to claim they last 3 -4 years!
    Mine are fine for a couple of months, single figure TDS, then it slowly but surely starts to creep up.

    I don't know if its something I'm doing wrong? My RO has 2 100GPD membranes, I change the filters regularly and flush it every day.
     
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  2. Smurf

    Smurf Banned
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    Mine last me years so I don't understand why you keep changing them.

    Do you ever backflush the ro?

    Are you also aware of ro tds creep and what it means?
     
  3. Smurf

    Smurf Banned
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    What's your tap water tds and how much pure do you produce/use in a day?


     
  4. Eclipse

    Eclipse Well-Known Member
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    Mine are still going after 2 and a half years, they last longer if you keep the other filters tip top. Less in = longer lasting. My tap water is ~250ppm.
     
  5. Daftoldgit

    Daftoldgit Member
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    Smurf, I'm not sure what you mean by backflush- I open the little flush tap thing thats fitted on the waste tube. Is that backflush?

    The tapwaters about 300ppm, I use about 200 - 250 litres a day.
    The waters usually at about 45 PSI, but sometimes drops to 35 or less...

    The TDS creep, I just read up on it, seems kinda like a temporary thing when 1st you turn it on?
     
  6. doug atkinson

    doug atkinson Well-Known Member
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    Where about's are you located as often this can be down to the water quality destroying membranes quickly. In the Wiltshire area people go through a lot of membranes and we had one analysed and it was totally solid with calcium deposits.
     
  7. Smurf

    Smurf Banned
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    #7 Smurf, Jun 20, 2014
    Last edited: Jun 20, 2014
    Some may call it flushing and others backflushing when they turn the flush tap to on position to force water back over the top of the ro membranes to help clean them.

    Howerver some don't bother turning the flush tap on but just what they call flush the system through without the di connected so the water still in the system drops down to the lowest tds. Then they connect the di back up to it so to save killing the small amount of resin more quickly in a 10" di canister.

    When you say the ro tds gets high is that when you take a reading from the ro outlet pipe when it first starts up?

     
  8. Smurf

    Smurf Banned
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    I live in wiltshire doug and my chepo 300 gpd ro has lasted me so far over 4 years whithout having to change the ro membranes.

    Hard water areas can definitely be no good for ro's but also lack of maintenance (back flushing) can’t help either I would have thought.

    Next ro I get was thinking of adding a water softener type setup before the ro so could you suggest the best way to go about this please. I know ionics use salt but I don't have a clue how it all works.

     
  9. Daftoldgit

    Daftoldgit Member
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    Hi, thanks for the replies so far- I've been away for a few days-
    Yes Doug I do live in Wiltshire actually, so maybe that's the problem?

    What part of wilts are you from Smurf?
    I'm in Melksham so not in the "chalky" area, although our water may be pumped from that part, I'm not really sure...

    I flush it by opening the tap tor 3 or 4 minutes a day
    The high readings are when its settled down, hours after turning the RO on, it starts off fine with a new membrane but gradually creeps up until after a few months its up to 30 - 35 ppm- this is before going to the DI.

    I wondered if its getting clogged by the occasions when the pressure drops down in the 30's? (usually after ten at night)
     
  10. Smurf

    Smurf Banned
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    #10 Smurf, Jun 23, 2014
    Last edited: Jun 24, 2014
    Wow! really I'm in melkshame too :eek:…get off my patch :D
     
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