what size softener do i need?

Discussion in 'Water Softener Forum, problems, installation and r' started by tomcat21, Feb 22, 2013.

  1. tomcat21

    tomcat21 New Member

    Messages:
    7
    Location:
    windom,mn
    Here are some specs and information.

    7 people in the house. 2 adults, 4 girls ages 6-12, 1 boy age 14.

    Actual water usage from city water bill (avg. for past year)= 46 gal/per person per day. high month avg was 61 gal. per day. low month avg. 37 gal. per person per day. I would say the norm would be around 50.

    3/4 inch plumbing. Water pressure to house is approx. 60 psi

    city water

    city water specs:
    hardness 25-27
    ph: 7.2-7.8
    iron .08
    manganese .03
    alkalinity- filtered 294mg/l
    TDS-456-470 mg/l ( I think he also divided these 2 figures by 17.2 and got 27 and 26.5 respectively)

    http://www.windom-mn.com/wp-content/uploads/2012/06/2011-water-quality-report.pdf (this is a link to my city water report. It will list some things I have not already listed.)

    I have a flow rat of around 6gpm at tub and downstairs faucet where softener will be located. Kitchen sink and other faucets are much lower than these 2.
    Last edited: Feb 22, 2013
  2. mialynette2003

    mialynette2003 Member

    Messages:
    731
    Location:
    Ocala, Florida
    Use the high usage to figure the softener size. 61*7= 427 gallons used per day. 427*32.4 (compensated hardness)=13834.8 grains removed per day * 7 days= 968443.6. You should get a 3 CF softener.
  3. tomcat21

    tomcat21 New Member

    Messages:
    7
    Location:
    windom,mn
    Thanks for the reply. I am confused on what type of resin to get. I have heard of 8% or 10 % cross link. I know the city does use chlorine to treat water. Also is it true that setting the salt dosage for a higher amt will clean the resin bed better? Not even sure what this means. I have heard of setting at 6 lbs per cubic ft and also setting the softener to like 10lbs/cu ft. What is channeling and would I run into that problem if I got a 3 cu ft softener and water usage drops way down like say in 7 years when kids are graduating?
    Last edited: Feb 22, 2013
  4. mialynette2003

    mialynette2003 Member

    Messages:
    731
    Location:
    Ocala, Florida
    1 CF will yeild 30,000 of hardness removal (some say 32K) but you must use 15 lbs of salt. If you use 6 lbs you get 20,000. So you get better salt efficiency by using lower amounts not cleaner resin with higher amounts. 10%crosslink resin will stand up longer to chlorinated water than 8% but, over time, they both will need to be replaced. Channeling is when the water follows a channel through the resin instead of passing through all the resin. Channeling allows hard water in the home. You may never have a channeling problem. Using an under bedding in the system will help prevent channeling. Once the kids leave, you will have longer runs between regens but not channeling problems. You city water will have enough flow rate to properly regen a 3 CF unit.
  5. tomcat21

    tomcat21 New Member

    Messages:
    7
    Location:
    windom,mn
    Thank you ! I am going to purchase one within a few days. Any good recommendations? I am not going to Home Depot or any big box store. I also don't think I really need to pay $3,000 for one either.
  6. ditttohead

    ditttohead Water systems designer, R&D

    Messages:
    1,827
    Location:
    Ontario California
    PM sent.

    A 2.5 Cu. Ft. system may be a little undersized from a technical standpoint, but the physical size of the system will probably a lot nicer. The 3 Cu. Ft. system uses a 14x65 tank, the 2.5 is a common 13x54 tank. That extra 10 inches of height is considerable.

    The 2.5 will be slightly less efficient, but the difference may only be a bag of salt per year.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,519
    Location:
    Cave Creek, Arizona
    quote; The 2.5 will be slightly less efficient, but the difference may only be a bag of salt per year.

    It will probably be JUST as efficient, just need regeneration more often because of the smaller capacity between regens, the TOTAL salt per year should be the same.
  8. ditttohead

    ditttohead Water systems designer, R&D

    Messages:
    1,827
    Location:
    Ontario California
    Dont mean to disagree, but a larger system will typically use less salt.


    The efficiency of a single tank softener is based on the amount of the reserve that is or is not consumed prior to a regeneration. By extending the days between regeneration with a larger tank, the systems efficiency becomes better. The difference between a 2.5 CF and a 3 CF should be minimal.

    14000 grains per day / 72000 = 5 days between regenerations, so a potential loss of a days worth of capacity = 14,000 grains of potential inefficiency per regeneration cycle.

    14000 grains per day / 60000= 4 days, so a potential loss of 14000 grains per regeneration


    A little long on the math, but if we average the loss at 50% of a days capacity, the 7000 grains, times 91 regenerations, vs, 73 regenrations is a difference of 126,000 grains annually, or approximately 42 pounds more salt per year. These are obviously only estimates, but they are fairly accurate. So like I said, about 1 extra bag of salt per year.
  9. Gary Slusser

    Gary Slusser That's all folks!

    tomcat21... you won't have iron in your chlorinated city water and you don't add anything because of the TDS. Use 27 gpg and 60 gals/person/day and I'd go with the 3.0 cuft but not the K of capacity or gallons for 7 days between regenerations because your salt efficiency would be terrible (2000+/- grains/per lb). Max K of a 3.0 cuft is usually figured at 90K and to get that you need 15 lbs/cuft of resin. So the 3.0 cuft would be too small for any better salt efficiency without using a lot more city water for more frequent regenerations.

    And you don't want to size or program so that the K of capacity constantly gets you into into the reserve capacity before every regeneration.

    You say like 6 gpm for your flow rate... that would not pass code so how did you get the 6 gpm? Your tub may have a mixing/tempering valve on it that reduces the flow. To figure peak demand flow rate you add up all gpm from all the fixtures in use at the same time. That tub and sink = 12 gpm. And codes require using the max gpm from all fixtures as if they are all using water at the same time... The constant SFR gpm of the cuft volume of resin in the softener has to be higher than that gpm or it can't remove all the hardness.

    You don't mention how many bathrooms and if any multiple shower heads or jetted tubs etc.. A 3.0 cuft would give you 18 gpm constant service flow rate(SFR). And with 60 psi city pressure (and above), with 3/4" line you can exceed that if the fixtures demand it. Then you would need larger than a 3.0 cuft.
  10. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,519
    Location:
    Cave Creek, Arizona
    Unless i am reading your math wrong, 14k grains over 5 days is 70k grains which is 2k grains per regeneration, and 14k grains over 4 days is 56k grain which is 4k per regeneration. It appears that both of these calculations ignore a "demand" meter to give maximum usage between regens. Over a 20 day period the larger one will regen 4 times and the smaller one 5 times, which means that, using your latency figures, they would "waste" 12k capacity every 20 days, which seems to be a lot less than your calculations.
  11. tomcat21

    tomcat21 New Member

    Messages:
    7
    Location:
    windom,mn
    I timed how long it took to fill a 5 gallon bucket and divided by 300 or whatever the formula called for (cant remember the exact number) I also used a one gallon pail for kitchen sink faucet and stopped filling after 10 seconds.(Used a different equation to figure gpm on this one.)

    What is code? Is my gpm too high or too low?

    kitchen faucet=2gpm
    main bathroom: faucet=1.2gpm
    main bathroom:shower=1.6gpm
    main bathroom: tub=4gpm
    small bathroom: sink faucet=2.7
    downstairs shower: 1.7gpm
    downstairs sink: 4gpm (this sink is rarely used. only for cleaning paint brushes and rollers mainly)

    I must figured the 6 gpm wrong the first time I tested. The numbers above should be close.

    I have a main bathroom upstairs with a tub,shower,toilet and sink.
    smaller bathroom upstairs with sink and toilet.
    downstairs has a shower, toilet and sink.

    When I tested, I just had each individual fixture on. I did not have them all on at the same time. Also using the upstairs tub/shower, you would only be using one or the other.
    Last edited: Feb 25, 2013
  12. tomcat21

    tomcat21 New Member

    Messages:
    7
    Location:
    windom,mn
    Anyone there? I think I have given all the information that I know of to make a decision on a softener. Can someone tell me what I should purchase and why would the size you recommend be the best choice/most efficient. Thanks to all of you for your help
  13. mialynette2003

    mialynette2003 Member

    Messages:
    731
    Location:
    Ocala, Florida
    Get a 3 CF Clack softener. For 10 years I would not sell a Clack system because I wanted to see if it would last the test of time and it has. Clack has a varity of adjustments to fit any house hold.
  14. tomcat21

    tomcat21 New Member

    Messages:
    7
    Location:
    windom,mn
    would that work with 3/4 plumbing?
  15. ditttohead

    ditttohead Water systems designer, R&D

    Messages:
    1,827
    Location:
    Ontario California
    Clack valves are very good and the WS1, 7000, etc. will all work with 3/4" plumbing. UPC only states that you can not reduce pipe size for a softener, you are allowed to put in a larger system. Clack, Fleck, and Autotrol will all work with 3/4" plumbing and all are excellent valves. If you stick with any of these systems, you will do just fine. All of the systems have their quirks and problems. The only valve that appears to have taken care of all the complaints I have with all of the manufacturers designs is a valve that wont be released until late this year, or early next assuming everything goes correctly. It will be a USA made valve that is fully programmable, has 1-1/4" flows, DC drive, single piston design w/ standby, staging, series, alternating capabilities without any external devices. (MAV, Aquamatics, solenoids, NHWBP, etc.) Full color large touchscreen, and much more. Anyone coming to the WQA show in Indianapolis?
  16. Gary Slusser

    Gary Slusser That's all folks!

    The softener has to treat the max gpm you run through it. So you add up the fixtures you usually use at the same time.

    Most resin manufacturers say their regular mesh resin will treat up to 5 gpm per cuft. That is a bit on the conservative side.

    As to efficiency... normally that is figured as you would figure fuel efficiency in a vehicle; fill the tank, drive X miles, refill and then divide the miles driven by the gallons used. You don't use remaining gallons or any type of evaporation rate....

    Salt efficiency is the regenerated K of capacity (30K per cuft) divided by the lbs of salt used at a max of 15 lbs per cuft or less. 30,000 divided by 15 lbs gets a 2000 grains/lb salt efficiency. So the fewer lbs used the higher the salt efficiency.

    I.E. if you use 15 lbs/cuft and have a 3 cuft softener the total is 45 lbs and that gets you 90,000 grains of regenerated capacity at 2000 grains per lb of salt.

    Same 3.0 cuft softener 'short salted' would be say 6 lbs/cuft for a total of 18lbs/regeneration and that would get you 20,000 grains per cuft per regeneration or 60,000 total for a 3.0 cuft and 60,000/18 lbs. shows a 3333 grains/lb salt efficiency.

    That's a 1333 grain per lb increase in salt efficiency, or some 30+% increase.

    But... you get more frequent regenerations at 18lbs each over whatever time frame you want to use UNLESS you buy a larger (cuft) softener that allows the 90,000 capacity with 6lbs per cuft. Which gets you the 90K at 3333 grains per lb and the same number of regenerations as the 3.0 would get you. And, you can usually program to use damned near if not the same number of gallons of water per regeneration as would be used in the smaller softener.

    Most residential softeners sold today are metered, meaning they use a water meter to trigger a regeneration. That's called a demand regenerated softener and most will be delay regeneration meaning the regeneration will be started at the industry standard 2:00AM although most can start at any time of day or night but, you want the regeneration when water is not being used in the house/building or you get hard water past the softener until the regeneration is finished.

    So... metered/demand based softeners regenerate when a set number of gallons of hard water is run through the unit.

    You get the number of gallons by multiplying the total gallons used per day (7 * 60 = 420) by the number of days you want between regenerations (8) = 3360 (gallons on the meter).
    Then 3360 times the compensated hardness (27) = 90,720 rounded up to the next 1000 = 91,000. Then 91,000 divided by say 20,000 (that's 6 lbs/cuft or a salt efficiency of 3333 per lb/cuft) = 4.55 cuft softener, and 6 lbs times 4.5cuft = 27 lbs. per regeneration or, 91,000/3333 = 27.3 lbs round to 23.5 if the control valve allows it, otherwise go to 28 lbs.

    But... there's always a BUT...

    If the control valve doesn't have the variable reserve feature, you must subtract a day's worth of capacity (or gallons) for the reserve so... 91,000 - 12,000 (one day) = 79,000 divided by 420 gals/day = 2940 gallons on the meter.

    So I suggest 7 * 60 = 420 * 27gpg = 11,340 grains per day, times 8 days = 90,720 round to 91,000 (91K) and that divided by a salt efficiency of 3333 = 27.3 lbs of salt per regeneration or round to 27.5 and if the valve won't allow that, then 28 lbs in a 4.5 cuft softener.
  17. tomcat21

    tomcat21 New Member

    Messages:
    7
    Location:
    windom,mn
    Thank you Gary! So you are suggesting a 4.0 or 4.5 cu ft softener correct? What are your thoughts on the 2510 fleck valve? Heard good things about it but not sure if it has the variable reserve feature or not. Also, in 5 years we will be down to 5 people in the house and I also plan on putting on a bypass valve so any outside water usage will not be going thru the softener. (My old/current softener does not have a bypass) We do water the yard, kids use the sprinkler, wash cars, etc. In 10 years, down to 3 people. Knowing that, would you still recommend that size? Also, if you did purchase a the bigger unit and water consumption drops like it will, can you program these bigger units to still be efficient? I realize regenerations will be less frequent but is that a concern I should have? Would it still be economical rather than having to downsize in the future? Also, one guy told me they set their softeners to 10#lbs and not 6#lbs. He said it cleans the resin bed better or something like that. Is there any validity in that and why is that such a big deal or isn't it?
    Last edited: Feb 27, 2013
  18. Gary Slusser

    Gary Slusser That's all folks!

    If you don't want to go that large, you go smaller and regenerate more frequently with more salt usage.

    The 2510 is an excellent valve.

    You can change the programming on all Autotrol, Clack or Fleck control valve anytime you need to.

    If you are using softened water at outside faucets then you are using more than 60 gals/person/day and a way around that is to put the softener in bypass while doing that and then putting it back in service when done.
    .
    Most dealers/salespeople that make a comment like '10 lbs cleans better', don't understand ion exchange very well and are building in a fudge factor so they don't mess things up. It takes 2 sodium ions to 'clean' 1 ion of 'hardness' off the sites on a resin bead. All sodium ions above those that remove hardness ions are wasted. And in the 6 lbs/cuft there is some waste.
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