variable bringing

Discussion in 'Water Softener Forum, problems, installation and r' started by lifespeed, Jun 7, 2012.

  1. Tom Sawyer

    Tom Sawyer In the Trades

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    He apparently "doesn't know what he doesn't know" LOL
  2. gojoe3

    gojoe3 New Member

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    lifespeed,

    In reference to softener resin health, I would guess that backwashing on a more regular basis (like 8-10 days versus 3 weeks) would better maintain the resin bed because backwashing redistributes the resin in the bed (fluffs it up) which will assist in preventing "channeling".

    Here is a link to an article on brine efficiency and variable brining:
    http://www.watertreatmentguide.com/achieving_brine_efficiency_in_softening.htm



    I copied and pasted information on backwashing from a portion of a technical paper I got from this link :
    http://www.steamgenerationsystems.c..._water_treatment_3/raw_water_treatment_3.html

    It references zeolite resin but I would assume the same is true for the resin you are using.

    Here it is :

    Backwash. During the exhaustion or service cycles, the downward flow of raw water caused suspended matter to accumulate on the resin bed. The resin is an excellent filter medium. Backwashing is an upward flow of water which passes through the underdrain system, up through the resin bed, and out the service water distributor to waste. This reverse flow lifts and expands the resin bed by placing each bead in motion. In this manner, the bed is regraded while particulates and resin fines are removed.

    Regrading or classification of the zeolite resin brings smaller beads to the top of the unit; larger beads go to the bottom. This enhances proper brine distribution. Expansion releases material accumulated within the resin bed and fluffs the bed to allow for efficient brine-resin contact. Particulate matter and resin fines must be removed to prevent channeling, high pressure drop and poor kinetics.

    Backwashing should be carried out for a minimum of 10 minutes or until the backwash water effluent is clear. The backwash water flow rate should be sufficient to produce a minimum of 50% bed expansion, yet not excessive enough to cause loss of resin.

    The percent bed expansion resulting from a set flow rate is a function of the backwash water temperature. At a given flow rate, the lower the temperature, the more the bed is expanded. Due to increased viscosity of the water, adjustments in backwash water flow rates should be made as water temperatures vary seasonably. Backwash rates usually vary from 4 to 8 (ambient temperature) and 12 to 15 (hot service) gpm per square foot of tank area, but each manufacturer's recommendations should be carefully followed.
  3. Tom Sawyer

    Tom Sawyer In the Trades

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  4. Gary Slusser

    Gary Slusser That's all folks!

    How does a less than 6lbs/cuft salt dose reduce water quality? At the end of a regeneration all the used resin is fully regenerated the same as it is with 6 lbs or more.

    Yes I assumed a disposable cartridge filter, not a backwashed carbon filter.

    You don't have over sized plumbing, nor do you have over sized water treatment equipment. But you are going too long between regenerations.
  5. Gary Slusser

    Gary Slusser That's all folks!

    In my 20 years as a local dealer, I had two Culligan dealerships in my service area and I sold a lot of softeners to their dissatisfied monthly exchange tank type customers. I also sold a lot of softeners to their rental softener customers but....

    In over 25 years I've never heard from anyone with a longer than once a month exchange tank type softener but I would think most of them might be dissatisfied also.

    A nationally recognized Culligan sales women, with 20+/- years with the one dealership told me that the attrition rate of the exchange tank resin was quite high, something like 20%/year if I recall correctly, and it was due to how the resin was regenerated. The dealership she worked for was only 1.5 miles from my place and it was in the same location since it was started in 1962.

    Strange that you mention exchange tanks when both those very old dealerships started getting rid of their residential (if not commercial too) exchange tank service in the early to mid 1990s.
  6. Gary Slusser

    Gary Slusser That's all folks!

    You can be sure the thread wasn't closed because of you or anyone else posting that link.
  7. Tom Sawyer

    Tom Sawyer In the Trades

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    Indeed, I am more than sure that the link was not the issue LOL.
  8. ditttohead

    ditttohead Water systems designer, R&D

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    I know someone who said something that agrees with me so you are wrong. Huh???

    In regards to portable exchenge tank systems, I design them. Batch regeneration methods, in tank regen, mini, standard, and trucked transfers, I design those systems. I think my knowledge would be a little more than a salesperson for Culligan. Your strange need to argue is difficult to understand. The long time between regenerations that is common in many portable exchange tank systems is primarily commercial low water use applications. Steam boilers, heating hot water water systems, etc. Many facilities will store a bank of extra tanks, either softener or DI for months at a time before they will go into service, and when they do go into service, they can stay online for many months, no problem. Now for your 20% attrition rate... 5 years for resin is not that bad, especially if you understand the batch regeenration processes, which you do not.

    Resin should be regenerated regularly, yes. Regenerating it infrequently in a residential application with decent quality feed water will not have a detrimental affect to the resins life or softening ability. If you read the manufacturers recommendations for RO pre-filters, 6 months is the normal changeout for the pre-filter, this is a generic statement, common sense would also indicate that water conditions and applications vary, so annual filter changeouts are more common on cleaner water supplies. Same goes for water softening resin or any other water treatment media or methedology. Technically speaking, his 1.5 cu. ft GAC has a service flow rating of 4.5 GPM, which is technically, according to the manufacturer, undersized.

    lastly, < 6 pounds will produce a slightly harder water, this is not a debatable issue, it is simply an ability to do math and understand charts. Do you even own a hardness ppm test kit? I will assume no, so you would not understand the testing protocols for determining this. Regardless, most people, not all, are happy with the quality of the water that regenerating a softenr with 4 pounds per cu. ft. will provide.

    Déjà vu, I have already said this before, and we do not necessarily disagree, you are just determined to argue.
  9. Gary Slusser

    Gary Slusser That's all folks!

    It's a bit more than that and you should know it. I see below you are talking about exchange with boilers etc. etc.. Here we usually talk about residential water quality to novice homeowners. And you keep throwing out all sorts of info that doesn't apply to them and then say I argue with you... that's convenient for you but incorrect.

    So you design them, I don't see any mention of residential use in all that bloated ego stuff Alan but, how does any of that help the OP in this thread and any other homeowners that will read this in the future?

    The Culligan lady and I back then and I now in this thread, were talking about residential exchange tanks, not commercial applications.

    A... we were talking about a residential softener sitting around for weeks or a month or longer between regenerations until you went off into commercial exchange tanks sitting around for months to back up your claim of it not being a problem in residential softeners.

    IMO not many homeowners are going to care about how long commercial exchange tanks sit around but...

    Trust me, those same homeowners will want their resin to last well past 5 years.

    And the batch regeneration was one of the things that caused those Culligan dealers to stop their exchange tank programs.

    That is what I said and you disagreed but then I didn't put conditions on it because neither you or I know anything about the "quality" of the feed water but, I know all waters have a varying amount of invisible dirt in them and I respond accordingly while you respond as if there is no dirt in all waters. Do you think there are any well owner OPs reading this, I do, and if so, what would you tell them?

    They, the resin manufacturers, also say for residential softeners that on average weekly regeneration is best but, again, off you go into RO prefilters when I and especially the OP, are talking about his residential softener and how long he should go between regenerations.

    And had I mentioned his filter being undersized, you or someone else would have disagreed, but please explain to Lifespeed why that is not a good thing.

    Slightly harder water on a ppm basis but not with the 5B test kit you suggest all homeowners use because it does not measure ppm, only gpg. Am I right or arguing with you?

    Also, "most people" can feel a grain or two of hardness getting through their softener but, you go on about the FEEL of the water not being a good enough "test"... so how is it that those people in your "not all people" are going to know they have a few ppm of hardness in their softened water if they don't FEEL it?

    Do you have a test kit suggestion for them so they can test their water for ppm of hardness daily? Do you really believe a homeowner is going to do that because they are that anal?

    LOL Actually I'm determined to keep you on topic and root out all your extraneous, long winded, ego driven BS that has nothing to do with the residential OPs' questions or problems.
  10. ditttohead

    ditttohead Water systems designer, R&D

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    I think I understand the problem, you are unable to read a post as a whole, you have to break every post into individual sentences, not quite understanding that the post is meant to be read as a whole. Now I understand... it makes a lot more sense.
  11. F6Hawk

    F6Hawk New Member

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    Perhaps lifespeed realizes that lower brine amounts leaves more hardness in the resin. And then, when soft water makes its way down thru the resin, some of the sodium departs said soft water, and regenerates the resin below that wasn't regenerated due to less salt being used, and therefore, some "hardness leakage" may occur.

    Now, since water is still considered soft from 0-3 gpg, it will probably not be a huge factor to most residential applications. But you asked HOW it affects water quality, not if the end user CARES if it does.
    Last edited: Jun 10, 2012
  12. Gary Slusser

    Gary Slusser That's all folks!

    We are talking about hardness in the softened water, and dittohead is bringing in ppm of hardness instead of talking gpg of hardness that is used in residential softening but..

    Perhaps you and Lifespeed don't understand that whatever the high efficiency salt dose is it will be sufficient to regenerate the capacity of the used resin. We started out with fully regenerated resin, used say 20k and regenerate the 20 K, where do you see resin with hardness on it?

    I think you've taken to heart some of the twin tank softener selling guys marketing hype about upflow/counter current regeneration. That should only be applied to boiler and other waters that require a max of X number of ppm and no more. They don't deal with gpg as residential softening does.

    That 0-3 gpg, that is of the raw water and is used to determine IF 'you' would benefit from buying a softener.

    When you have a softener, it should always produce water with no more than 1 gpg of hardness break through, so says the Water Quality Association.

    I say, if we can get it down to no more than 1 gpg, we can get it down to 0 gpg. And for many years I've done that for all sizes of houses, families and businesses regardless of their peak demand flow rates. But you don't have to believe me if you don't want to. Or you might want to try my way for a month or two and see for yourself. Does your 7000 record the highest gpm for you? If not and you over run the SFR of the resin, you might mistakenly think you're not regenerating with enough salt.
    Last edited by a moderator: Jun 11, 2012
  13. lifespeed

    lifespeed Member

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    implemented variable brining

    The reason for my inquiry about variable brining is I thought it might allow more-frequent regenerations for my 1.5 cu ft system without increasing overall salt useage, wasting salt/capacity. With moderate hardness of 7 grains, and low water use the capacity of 3857 gallons (not including additional 10% reserve) takes about three weeks to consume.

    So, my thinking is I will regen more often, even though I still have capacity left. But I'll use variable brining to implement brine fill first, wait 60 minutes (SV 60 in the programming?), and only use maybe 4.5 lbs per regen instead of the full 9 to regen 30K capacity of the system when it is used near capacity.

    So far it seems to be going through the regen fine. I noticed when I first switched modes (VT dfff, CT fdPb) to variable brining it seemed to activate the brine fill briefly, and displayed "UD sync" while it did this. I programmed the valve to begin it's cycle in a few minutes, and it appeared to go through the BF cycle with minimal time. I assume this was a result of it resetting capacity to full, so its calculation thought it did not need to add brine at all. I added enough water to dissolve 22 lbs of salt to make sure this regen would put the softener at full capacity.

    Will this work? I won't be able to observe the softener correctly meter the brine until the next regen. I assume it will only fill for half the time it normally would, if the capacity is only half used.

    Is a softener at full 30K/ft capacity at the end of a regen, even if less salt than 15lbs/ft was used? eg: started at 30K capacity, used 20K, then regen with 6 lbs/ft to get back to 30K "full" capacity. Or is the capacity only 20K now? In other words, do you use capacity starting at full, or add capacity starting from empty?

    I checked the hardness before starting the regen and it was 0 gpg. But I was still 600 gal short of the 10% safety margin, even though it had been 21 days.

    DF Gal
    VT dfff
    CT fdPb
    C 30,000
    H 7
    RS SF
    SF 10
    DO 10
    RT 2:45
    B1 10
    BD 60
    B2 6
    RR 8
    BF 13
    SV 60
    FM t1.2
    Last edited: Jun 10, 2012
  14. F6Hawk

    F6Hawk New Member

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    Assuming a 1 cu ft softener, it takes 15 lbs to regen 30K, 10=27K, 8=24K, 6=20K, 4=16K

    If you set your salt for 6 lbs or 20K, and it starts with 30K, then you will regen 20K when it reaches that 20K worth of softening. In a perfect world, said softener will use 20K, still have 10K of capacity, and regen 20K.
  15. F6Hawk

    F6Hawk New Member

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    Did you mean CT fdbr?
  16. lifespeed

    lifespeed Member

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    No, my controller really displayed that. What you showed is in the 7000SXT service manual,
    not in my unit firmware of recent vintage.
  17. Gary Slusser

    Gary Slusser That's all folks!

    It would if you have the variable brining feature on your control valve but... I don't think your version of the 7000 has variable brining, does it? But then variable brining also uses a lot more water. IMO 3 weeks is way too long between regenerations.

    Yes that is how variable brining works, but 60 minutes is too short and should be at least 120 minutes so all the salt can dissolve into the refill water before it is used.

    Question, when your vehicle gets down to say a 1/4 tank and you refuel, did you waste the mileage of the 1/4 tank?

    Well I went and looked it up.... If you have the SXT timer, your 7000 does not have variable brining, it has variable RESERVE.

    Check it out;
    http://www.pentairwatertreatment.com/en-us/Products/ResidentialControlValves/Fleck 7000SXT.htm

    Using my old guy memory and then my calculator, I say 30K - 20K leaves 10K in the bed/tank and then regenerating the used 20K + the remaining 10K that was left in the tank, I get 30K, although I only had to use 6lbs/cuft (9 lbs) of salt to get the 20K per regeneration instead of 15lbs/cuft (22.5lbs). Now it is an old calculator I'm using...

    Let's us say you have a 20 gallon fuel tank in a vehicle and a 1/4 tank of fuel on the gauge. You fill it with 3/4 of a tank and have a full tank, and it only cost you the price of 3/4 tank instead of the whole 20 gallons. Does that help?

    As to the programming, I am not up on it enough to know if it is right or wrong.
  18. lifespeed

    lifespeed Member

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    Does the fullness of your gas tank depend on the amount of gas it is soaked in before draining out the all the gas you will use to operate your car? Pretty sure the gas tank analogy is not valid . . .
  19. F6Hawk

    F6Hawk New Member

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    The gas tank analogy kind of works, LS... the tank's capacity is 20 gallons, you use 3/4 of it, or 15 gallons, and it will take 15 gallons to refill it. The last 5 were still there, if needed (kind of like a reserve), so they don't need to be replaced. (nvm if you have an innacurate gauge or other anamoly, we are talking capacity of the tank).

    For resin, if the capacity is 20K (1 cu ft @ 6 lbs salt), you use 3/4 of it, or 15,000 grains, and it will take enough salt to replenish the usage, with about 5,000 grains remaining in the resin which was not used. Provided you oversaturate with enough salt to replenish those used 15K grains, you now have a max capacity of 20K again. Now, it stands to reason that not 100% of the media will take on sodium, and therefore the next time, you may not have exactly 20K of capacity... but for all practical purposes, your water will be soft, and the little hardness that snuck by will go undetected. (Unless you are testing with something more precise than the Hach 5B)

    At least, that's how I understand it. Feel free to shoot down my theory, oh ye gods of sodium-enhanced water!
  20. ditttohead

    ditttohead Water systems designer, R&D

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    Fairly accurate. In the same way that non variable reserve is like adding 20 gallons to a tank, regardless of how much overflows and is wasted on the ground. The only real difference is that due to some algorythyms and efficiency anomlies, a variable brining system works best in an upflow application, (lets not get into that old discussion), and the efficiency gains are minimal unless your system is completely undersized or improperly applied.

    The gas analogy would be easier to understand in softening terms if gas only cost 5 cents a gallon, and you only filled your tank once a week, the savings of a few gallons is good, but is it worth it?

    The best application for a variable reserve softener is commercial or extremely high hardness residential where a 2 cubic foot single tank system is going to be regenerating less than every 4 days, but then again, a twin alternator should be used at that point anyways.
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