rise in ppm

Discussion in 'Water Fed Pole Cleaning' started by trevor peacock, Aug 14, 2016.

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  1. trevor peacock

    trevor peacock Active Member
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    I bought a 450gpd RO system from collinswaterproducts back in march, I use a booster pump to get the pressure up to 80psi, when I first set it up my water was 330 going in and about 10 coming out.
    It's gradually crept up to 20, I've changed the pre filters but it's still about 18.
    Anyone got any ideas what's occurring?
     
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  2. trevor peacock

    trevor peacock Active Member
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    just read a few threads and quite a few of you have got the same RO unit and are getting below 10, something must be wrong, i spoke to the guy at collinswaterproducts and he said you have to change the prefilters every 3000 us gallons which is about 11,500lts, I've done that with little difference as I said above.
     
  3. Trev81

    Trev81 Guru
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    Yes your RO membrane is getting older so its output will rise, try giving it a hour long flush and see if that lowers it a bit
     
  4. trevor peacock

    trevor peacock Active Member
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    I spoke to the guy at Collins and he said the flush is just to get rid of the stale water in the system and you only need to flush it for a minute a week. Is that not right?
    I only use about 2000 lts a month could my RO membrane deteriorate in 5 months, I changed the prefilters last week.
     
  5. spruce

    spruce Grand Master
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    I think you need to plug in each membrane separately and check the output of each of them. You should then be able to identify if just one of them is faulty or not. If they all produce similar results then the problem is most likely chlorine related.

    I don't know how Collins Water joins up their membrane housings. There are 3 ways suppliers and manufacturers do this;

    1)
    One of the ways was to feed the pure into the first membrane, take the waste from that and feed it into the input of the second membrane and do the same with the third. If they use this system then at a tap tds of 330, the last membrane in line is going to be working very hard. This is because the input is going to be very high. Its done this way to reduce costs and your water bill, especially important if you are on a meter. The down side is that the membranes don't last long.

    2)
    The water from the prefilters is split and it feeds the first and second membrane with 330ppm water. The waste from both of these membranes are joined and feed the third membrane. Pros and cons are similar to No1.

    3)
    The water from the prefilters is split 3 ways and feeds each membrane with 330 ppm water. The wastes are all linked together as are the pures. The benefits are that all membranes have equal work to do but the downside is that you will use more water.

    It could also be that chlorine is destroying your membranes. The c/b (carbon block) filter which removes chlorine should be changed at 11500 liters. This includes waste and pure. If your r/o has a waste to pure ratio of 3 to 1, then you are using 4 liters of tap water to produce 1 liter of pure.
    If you are using 2000 liters a month cleaning windows then you will have had 8000 liters pass through your r/o.
    If the manufacturers specs are right, then you should replace your prefilters every 6 weeks. So if you haven't changed prefilters in this time then chlorine damage is most likely the cause of your high tds. Changing prefilters now won't help if the membranes have been damaged by chlorine. Flushing won't help much either. Rectification is replacement of the membranes.

    I suggest Fiberdyne carbon block prefilters as they will remove chlorine from 38000 liters. But they are more expensive.

    -
     
  6. trevor peacock

    trevor peacock Active Member
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    I spoke to the guy from Collinswaterproducts again, he told me changing the prefilters wont improve the tds just make the RO membrane last longer, he said the prefilters last for about 8000 us gallons total water or 3000 pure.
    He also said the RO membrane will slowly deteriorate and a rise from 10 to 20 over 6 months is ok.
    He said it's up to the individual but he suggested changing the membrane when the tds gets to about 30.

    opinions please.
     
  7. doug atkinson

    doug atkinson Well-Known Member
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    Trevor pull one of the membranes out and see what make it is. Also see if it is coated with a white film as it could be calcium clogging up your membrane.
     
  8. trevor peacock

    trevor peacock Active Member
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    can I scrape any calcium off if it's there?
     
  9. doug atkinson

    doug atkinson Well-Known Member
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    Unfortunately you cannot
     
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