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woodwrkrz

setting up a fleck 9100SXT water softener control valve

woodwrkrz
10 years ago

I have a private well with the following water properties:
26 GPG Hardness
2.5 ppm Iron
0.5 ppm Manganese
This results in a total Hardness of about 40 GPG
4 persons in the household @ 75 g per day per person = 300 gallons per day
300 gpd * 40 gpg = 12000 grains of hardness per day
i installed a dual 12" x 52" tank system with gravel underbed and 2 cf of 10% resin in each tank. system has a Fleck 9100SXT control valve. The software has the cycles in the following order and I set each cycle to the minutes in parenthesis;
back wash (BW 10 min)
brine draw and slow rinse (BD 60 min)
rapid rinse (RR 10 min)
brine fill (BF 8 min)
by setting the brine fill to 8 minutes I am putting 4 gallons of water in the brine tank (0.5 gpm on label, but i measured it to confirm too) 4 gallons @ 3lbs per gallon is about 12 lbs of salt per regeneration. This will not "completely" regenerate 2 cf of resin (64000 grains) but should regen 40,000 grains which is where i set the software capacity (C) setting too. By "short" salting I should get better salt efficiency. NOW the question. I have read that a particularly when short salting it may be a good idea to have a second back wash cycle after rinsing to redistribute the resin bed. The 9100SXT software allows you to choose a different valve type which has 2 backwash cycles but I tried that and it was clear to me that there must some additional change in the hardware that makes it possible to actually implement a different cycle order (perhaps changing out cams?) Does anyone know much about this?

Comments (7)

  • AliceHasLeftTheBuilding
    10 years ago

    1st: You have a total compensated hardness of 43.5, not 40.

    2nd: 60 gpd per person is a more typical estimate for water use. Perhaps your family uses more water? This is neither here nor there at this point since you have already purchased the softener, but something to keep in mind for future.

    3rd: You have iron and manganese in high enough concentrations that you need to use 9 lb salt per cubic ft of resin. Brine fill should be 12 minutes. Then set your capacity to 51,000 grains.

    4th: You need to either use iron-removing salt, or do a periodic dosing with iron-out if you want your resin to last. What resin did you purchase?

    5th: You will need to contact your supplier to see if the specific valve you have will support the double backwash capability of the controller. If not, it is likely not worth the expense to make the change since your softener is not that large.

  • woodwrkrz
    Original Author
    10 years ago

    Thanks Alice,
    What hardness factors do you use for iron and manganese (I've been told anywhere from 3 to 5)?
    I chose the salt dosage after reading the linked reference Salt dosage rate efficiency document :
    http://www.watertreatmentguide.com/index.htm

    I assume if I go to a higher salt dosage with the attendant higher capacity I just go to longer times between regeneration and less efficiency which does not seem like a good idea with the iron content I have....

    Do you know if Iron out is particularly detrimental to septic tanks/latteral field (more so than salt)?
    Thanks

  • justalurker
    10 years ago

    deleted

    This post was edited by justalurker on Mon, Nov 4, 13 at 16:14

  • AliceHasLeftTheBuilding
    10 years ago

    What hardness factors do you use for iron and manganese (I've been told anywhere from 3 to 5)?

    1 ppm Fe = 5 pgp hardness
    1 ppm Mn = 10 gpp hardness I chose the salt dosage after reading the linked reference Salt dosage rate efficiency document :
    http://www.watertreatmentguide.com/index.htm

    The article you reference is actually here:
    Achieving Brine Efficiency

    It is a good reference, as far as it goes. Since the purpose of the article is purely to discuss how to achieve good salt efficiency, it does not go on to detail salt dosages in iron-laden waters. I assume if I go to a higher salt dosage with the attendant higher capacity I just go to longer times between regeneration and less efficiency . . . .

    Don't assume - calculate. You will regen every 3-4 days instead of every 2-3 days. You will also use up to 30 lb more salt each month. . . . which does not seem like a good idea with the iron content I have....

    Incorrect. In the article you reference you seem to have missed this paragraph: Typically these limits in salt efficiency are determined by the water's tendency to foul the resin and injectors with iron and sediment, and treated water hardness requirements. Low salt doses increase treated water hardness concentration. Removing iron from a softener bed requires higher concentrations of salt. Finally, smaller brine injectors are required for low salt doses as these small injectors are more susceptible to plugging with iron and sediment. Therefore, in applications with iron or where low hardness leakage is required, softeners are seldom run at maximum salt efficiency.

    The article does not provide any details about what salt dosage is appropriate for waters containing iron. Your water, with 2.5 ppm Fe and 0.5 ppm Mn, needs a salt dosage of 9 lb/cu ft if you expect your softener to continue to perform as it should.

    This post was edited by aliceinwonderland_id on Mon, Nov 4, 13 at 11:45

  • woodwrkrz
    Original Author
    10 years ago

    Thank you Alice,
    That was very helpful. Would switching to Mortons rust remover salt be as effective as using iron out? i know it would probably cost more but it would be a little more convenient.

  • woodwrkrz
    Original Author
    10 years ago

    Thank you Alice,
    That was very helpful. Would switching to Mortons rust remover salt be as effective as using iron out? i know it would probably cost more but it would be a little more convenient.

  • AliceHasLeftTheBuilding
    10 years ago

    In theory, it may not be quite as effective. However, in practice it will be more effective if you are like almost every other homeowner and tend to forget or put off periodic maintenance items. Using IronOut is very effective, but a pain if you do it right.