Need capacity/size advice

Discussion in 'Water Softener Forum, problems, installation and r' started by somedumbname, Jun 10, 2010.

  1. somedumbname

    somedumbname New Member

    Messages:
    7
    Location:
    Cincinnati
    I thought I should break this out into a new thread since I've decided I'm going with the Fleck 9000 SXT vs. the metered unit. I'm looking to order the system soon, but I want to get unbiased opinions on what capacity and size I need before I purchase.

    Hardness of the incoming water is around 27-30gpg. No iron, <0.5ppm chlorine, trace amounts of other contaminants. (City water).

    The problem I'm having figuring out which size to get is based on current vs. future needs. Currently, I'm the only one living in the house, occasionally having anywhere from 1-6 other people "living" here over weekends and whatnot. So for my water situation currently, it seems that the 9000 SXT twin-tank 48k gr capacity would be a good choice.

    However, it seems like if I end up having 4+ people living here on a consistent basis, the 48k gr capacity will not be very efficient, and will regen every 3-4 days. Am I correct in that assumption?

    The house is 4 br, 2.5 bath with the potential to be 5 br, 3.5 bath with a finished basement. 3400 sq ft, so there's more than enough room to have potentially 5-8 people living here once I have kids. The price difference to go up to the 64k gr twin-tank setup is an extra $170. I'm starting to think that it would make more sense to just bite the bullet and get the higher-capacity setup right now, rather than need to upgrade tanks in the future at a higher cost.

    So my questions I guess are:
    • Am I correct in looking at these capacities (48k vs 64k)?
    • Am I correct in assuming that upgrading tank capacity in the future (with the added cost of extra resin needed) would be much more expensive than the $170 up-front costs?
    • Is there any problem in having the much higher capacity now even though I would only really need it on occasion?
    • As long as I'm getting the SXT, if I'm not using capacity, what's the longest amount of time I should let water sit in the tanks? I've read anywhere from 9-14.

    Thanks in advance for any advice you can give me. Being my first house (and first experience with water softening), I'm in desperate need of expert opinions from people not trying to sell me stuff. :)
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,811
    Location:
    Cave Creek, Arizona
    You soften the water you use, and regenerate for that amount of water. Whether the softener regenerates every two weeks or every other day, assuming it has a demand meter to determine WHEN it should happen, it costs you about the same either way.
  3. Akpsdvan

    Akpsdvan In the Trades

    Messages:
    1,486
    Location:
    Alaska
    If you go to big there is the chance of Channeling, water going the easy way through the media.

    With no Iron in the water I would stay with a unit that can handle the peak flow rate for your home.
  4. somedumbname

    somedumbname New Member

    Messages:
    7
    Location:
    Cincinnati
    Thanks for the advice. I had not heard of channeling to this point, but after searching for it I can see how that would be a serious problem. It's just a bit confusing because it seems like every website has its own way of calculating capacity. I have been reading through all of the extremely long discussions on here going back and forth about size/capacity, and it's all somehow blindingly simple and annoyingly confusing at the same time...

    I'm guessing based on the responses that my math isn't throwing up too many red flags at least. I did notice that I didn't mention the amount of resin in the system I'm looking at. It's listed on their website as 4 cu ft of resin (2 cu ft per tank it seems?).

    So this is probably a dumb question, but if I'm only using 60-120gal/day on the 64k system, would I just reduce the lbs/cuft of salt I use? Also, if anyone has responses to the questions I listed above I would appreciate it. I'm trying to learn, but some of this is getting confusing to me due to differing opinions...
  5. Akpsdvan

    Akpsdvan In the Trades

    Messages:
    1,486
    Location:
    Alaska
    From what I have seen , often the capacity is the max salt per cubic foot, but that is often not the best bang for the buck..

    Drop me an IM as PM's are out ,, I have an Excel spread sheet that I did with some numbers.
  6. Gary Slusser

    Gary Slusser That's all folks!

    Now careful, I sell water treatment equipment including all types of water softeners...:D

    You get 30K @ 15lbs of salt per cuft of regular mesh resin. There is no such thing as "High Capacity" resin; there is regular mesh, fine mesh and SST-x0 resins. The difference between two or more of the same type resin is negligible and not worth the extra money you'll pay for them. 15lbs/cuft gets you 2000 grains/lb efficiency (30,000/15=2000). 6lbs/cuft gets 3333, over 50% better efficiency. Look at like fuel mileage, the higher the better.

    All softeners have an adjustable K of capacity.

    That is because you can set the salt dose lbs at any number of lbs you want to as long as the control valve or float in the salt tank will allow that number. Just like pressing your foot on the accelerator of a vehicle to go faster or slower, you adjust the fuel efficiency.

    If two or more softeners have the same type of resin and same cuft volume of that resin and use the same lbs of salt per regeneration, they have the same salt efficiency, period.

    It doesn't matter if brining/regeneration is done down flow or up flow, what size or brand of control valve or type or brand of resin tank (polyglass, SS, FRP), or the type of softener (cabinet, two tank or twin tank) OR the brand name of the softener.

    Anyone saying otherwise either doesn't know how to program softeners or is lying about or hyping or misrepresenting what they sell and want you to buy.

    So far you have not shown a need for a twin tank type softener. A regular softener would work fine. IIRC you are talking larger than you probably need for maybe a family of 4. Although I'm not recalling what peak demand flow rate the house may have as how you use water in it so I can't get into the constant SFR size of the softener. I also don't recall your hardness etc..
  7. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    Hardness of the incoming water is around 27-30gpg. No iron, <0.5ppm chlorine, trace amounts of other contaminants. (City water).

    The problem I'm having figuring out which size to get is based on current vs. future needs. Currently, I'm the only one living in the house, occasionally having anywhere from 1-6 other people "living" here over weekends and whatnot. So for my water situation currently, it seems that the 9000 SXT twin-tank 48k gr capacity would be a good choice.However, it seems like if I end up having 4+ people living here on a consistent basis, the 48k gr capacity will not be very efficient, and will regen every 3-4 days. Am I correct in that assumption?
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,811
    Location:
    Cave Creek, Arizona
    I have a problem with that statement. The K capacity is FIXED by the amount of resin in the unit. You can adjust how much resin is regenerated by the amount of salt you use, but if the amount is insufficient for the volume of water which has been used, the softener's capacity will be reduced by the deficiency. Using TOO much salt does absolutely NOTHING except waste the salt. A softener with a meter will allow the maximum amount of water between regenerations, and then use the proper amount of salt to COMPLETELY regenerate the mineral bed. Regeneration from the bottom lifts the resin bed and loosens it so the materials caught in the bed can be lifted and flushed to the drain. Doing it from the top, just compacts the material tighter.
    Last edited by a moderator: Jun 14, 2010
  9. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    It seems like we spend a lot of time thrashing the whole sizing issue on these threads. It's very hard to get two people to agree on anything here. I also question that post but though it was not worth going round and round all over again
  10. Gary Slusser

    Gary Slusser That's all folks!

    No, it is not FIXED until you set the lbs of salt used per regeneration. Without salt there will eventually be no capacity left in the resin, all the capacity would used up until you regenerate it with salt or salt substitute. Like a vehicle out of fuel, until you put more fuel in it it sits there looking pretty maybe but it's otherwise useless unless you nap in it.

    True. That's why you must do the math correctly to find out how much capacity is going to be used for the number of days, or gallons, between regenerations.

    To regenerate 1.0 cuft to 30K requires 15 lbs, 9lbs gets us 24K, 6 lbs gets us 20K etc. etc.. 30,000/by 15 shows we are getting a salt efficiency of 2000 grains/lb of salt used. 24,000/by 9 shows 2666 grains/lb (a better than 25% increase in salt efficiency) and 20,000/by 6 shows we get 3333/lb (another better than 25% increase in efficiency).

    Those figures are for every softener in the world per 1.0 cuft of regular mesh resin. AND, they also prove that the K of capacity of all softeners in the world is controlled (adjustable) by the lbs of salt used per regeneration.

    The only time the K of capacity is FIXED per cuft is in brand new resin because it comes from the factory fully regenerated. And as soon as hard water is run through it, we lose 2K per cuft, right off the top and that only happens the first time it is used. So as they call it, a "32K" becomes a 30K , and a 48K (1.5 cuft) becomes a 45K, a 64K (2.0 cuft) becomes 60K etc. etc. and then, then we get max capacity IF, ONLY IF, we regenerate with 15 lbs per cuft of resin in the tank. Less lbs = less K and higher salt efficiency. Raise the right foot off the accelerator your fuel mileage increases...

    And who runs their vehicle out of fuel before refueling just so they use all the fuel in the tank, like some softener owners are told to do by programming it for the max K of their softener's volume of resin before regenerating it....

    Here we have 30gpg. No iron, water, and 1 person in the house presently. So we take 60 gals/person/day times 30 gpg = 1800 grains/day used times say 8 days between regenerations = 14,400 grains and we round that up to the next higher K= 15K. To regenerate 15K/cuft, we need to find our salt dose lbs so, we pick the salt efficiency figure we want to use, say 3333 grains/lb and we divide 15,000 by 3333 grains/lb salt efficiency and find we need = 4.5 lbs, so we set the salt lbs at 4.5lbs and regenerate 15K about every 8th day for a family of one.

    Now 15,000/by 30 gpg water = 500 gallons on the meter of a demand initiated/metered type control valve that does not require a 24 hr reserve calculation such as the Clack WS-1 control valve (if we did have to set a 24 hr reserve, we must subtract 60 gallons from the 500 = 440 gals). And 500/60 gals/day we would regenerate a regular softener on average once every 8 days but...

    Here we don't have to set a reserve because he is going with a twin tank softener so... WITH A TWIN TANK TYPE SOFTENER, WE DO HAVE TO SUBTRACT THE GALLONS USED TO REGEN THE RESIN in each tank WITH SOFTENED WATER.

    And to do that, we must add up all the gallons of water used to regen a tank with softened 30 gpg hard water and then subtract that number of gallons from the meter setting. A 1.5 cuft will probably use say 45 gals, so we would set the meter to 455 gals between regenerations and 4550/60 = 7.5 days between regenerations instead of 8 days with a regular two tank softener instead of a twin tank type.

    Both types of softeners will regenerate the same K of capacity and use the same 4.5 lbs of salt per regeneration BUT, water efficiency will be higher with the twin tank AND, since there will be more frequent regenerations (every 7.5 days instead of every 8 days) the twin tank will use more salt on an annual basis.

    Now twin tank softener guys (especially Kinetico) will say NO, ours is more water and salt efficient, but the math doesn't lie. You can't look at just one regeneration, you total up on a weekly or other basis and compare totals over time.

    Here using 4 people is 4*60=240 gals/day * 30 gpg = 7200/day * 8 days = 57600 round to 58K. And we find he has what he mistakenly thinks is "48K" per tank but it is only 45K usable. So, we can only get a max of 45 K IF we set the salt dose lbs to 22.5 lbs per regeneration, which 45,000/by 22.5 lbs is a salt efficiency of 2000 grains/lb; that's terrible salt efficiency.

    So... he goes with a 2.0 cuft and now can use a salt efficiency of 3333 grains/lb which is 6 lbs/cuft and 2.0 cuft relates to 40K at 12 lbs. And off we go into 40,000/by 30 gpg water= 1333 gals minus the regeneration gallons (say 50) and he will get a regeneration about every 1283 or every 1283/240 = 5.3 days using 12 lbs of salt. To get 58K as above, he must use 29.5 lbs/regeneration and that is like 2000 grains/lb efficiency. And too long a time between regenerations.

    And until he finds the other 3 people to move in with him, he runs the possibility of channeling the resin bed and the only cure for that is more frequent regenerations.

    As we see, a meter has to be set and you set it based on using math to determine the proper number of days between regenerations based on the K of capacity you will use over that number of days but...

    We don't use up all the capacity before regenerating the resin any more than we run our vehicles out of fuel before refueling them so no, we do not COMPLETELY regenerate the whole resin bed because we didn't use up all the capacity; we regenerate the K of capacity we used just like filling up your fuel tank when you get down around a 1/4 tank or so. We refill what fuel we have used, not the whole tank worth.

    You are confusing the direction of backwashes with the direction of brine flow.

    Backwash is always UP from the bottom of the tank because the resin is compacted by the service flow going down through the resin bed compacting it and yes, without fluffing up the resin it will not be cleaned of dirt build up or more important possibly, it won't be brined properly.

    Brining flow direction is either co current regeneration (down flow, which is the normal way) or counter current (UP flow which is not normal). In some UP flow counter current regenerated softeners like Kinetico's smaller 2020, 2030 units, there is no backwash before brining. That's because they have a packed bed which means no freeboard space for bed expansion during backwash. That's how they use less water and, why they require a prefilter; that's to prevent the resin from loading up with dirt and having no way to rid the bed of it.

    Questions?
  11. Gary Slusser

    Gary Slusser That's all folks!

    We were posting at the same time.

    So state your way of programming for size, salt and water efficiency etc. and we'll discuss it OR, ask any questions you have.

    Note that above I didn't get into constant SFR sizing.

    BTW, all of what I have explained is easily proven by talking to any resin manufacturer.
  12. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    Ex: A family has 4 people with 33 grains per gallon hardness with no iron.

    4 + 1(for appliances) x 33 Grains/Gal. x 70 Gallons x 4 Days = 46,200 Grains. In this example, 46,200 grains of capacity is needed on average every 4 days. Because no iron is present, the low salt setting can be used. Select the softener that will provide more than 46,200 grains at the low salt setting.

    A water softener will remove clear water iron (iron in solution). When removing iron with a softener, compensate the hardness by a factor of 5 grains per gallon for every part per million of iron.

    Ex: A family has 3 people with 22 grains per gallon hardness and 3 parts per million iron.

    3 + 1(for appliances) x 37 Grains/Gal. x 70 Gallons x 2 Days = 20,720 Grains. In this example, 20,720 grains of capacity is needed on average every 2 days. With iron present, the softener should regenerate every other night and use the medium salt setting. Select the softener that will provide more than 21,000 grains at the medium salt setting.

    Your K capacity statement is technically correct but misleading.
  13. Gary Slusser

    Gary Slusser That's all folks!

    You have gone through how you arrive at the initial K of capacity which is substantially different than how I do it (which makes your K of capacity larger than needed) but... you aren't sizing a softener because you don't say how much resin or what type of resin.

    Then you also don't get into programming (which is part of sizing) because you don't say what lbs of salt to use for either example. And without how much salt you can't program or regenerate a softener.

    In the second example, I would not regenerate every other day because of 3 ppm of iron, man that causes very poor water and salt efficiencies and there's no reason to do that with only 3 ppm of iron.

    You're right it is correct.

    What part is misleading?
    Last edited: Jun 13, 2010
  14. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    And this is zactly why these threads always turn into the same old thing over and over. Do I really need to give a three page explanation on resin types and capacities? And even if I did all it would do is spawn yet another endless and confusing thread.
  15. Bob999

    Bob999 In the Trades

    Messages:
    448
    Location:
    Pennsylvania

    Unfortunately there is no way to have a civil discussion with Slusser because no matter what he posts he he will defend it as the righteous truth and no matter what the other guy posts Slusser will find something wrong and bash the poster. He even bashes the people coming here for advice for buying from others and not treating everything he posts as coming from an oracle.

    I have to admire your perseverance for trying yet again however.
  16. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    Bob, I'm not here to fight with the members. Perhaps someone should start a forum site for people that like to argue endlessly. A quick google of water softener sizing will reveal a whole lot of sites that have charts, formulas, some even let you put your numbers in and it spits out the information. Can you tweak the settings to get better salt efficiency? Sure you can but most folks are not interested in endless arguments or fiddling around with programming, timers and such. They just want the damn thing to work. As far as salt use, I doubt most folks give a hoot whether it goes through a bag or a bag and a quarter. Salt is cheap. I've been using the same sizing formula for 30 years or more. Never had a problem. Never had a complaint. I see little reason to change at this point. I see these forums as a place to help the poster, not argue with each other.
  17. somedumbname

    somedumbname New Member

    Messages:
    7
    Location:
    Cincinnati
    Sorry if I started something with my question. I do appreciate everyone's input though, and between this and searching through other threads I've been able to make my purchase. Thank you all for your help.

    I ended up going with the Fleck 9000 SXT, 12x52" tanks, gravel bed and 2 ft^3 of standard mesh resin per tank. I will likely have 3-4 people living here in the next year or two, and it just made sense to me to go a bit bigger now. Honestly, even if I went with 1.5 ft^3 of resin it's still overkill for just one person, so if I'm already going bigger than I currently need I figured I might as well size it to where it would work for either a small-sized family *or* a large-sized family, since the house can easily support one.

    If it weren't for sites like this, I probably would have just waltzed into Lowes or Sears and bought a brand name unit for not much less than what I paid for the system I ordered. :) Thanks to everyone who posts here, I'll be back if I have to look up answers for any installation or programming questions.
  18. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    You made a good choice.
  19. Gary Slusser

    Gary Slusser That's all folks!

    [​IMG] Originally Posted by Wally Hays [​IMG]
    It seems like we spend a lot of time thrashing the whole sizing issue on these threads. It's very hard to get two people to agree on anything here. I also question that post but though it was not worth going round and round all over again [/quote]

    And when I asked you what part is misleading you reply:

    Personally I think the threads go the way you want them to because you steer them that way. Just as you have this thread.

    Somedumbname, you had nothing to do with the way this thread went.
  20. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    Well Ok, I'm an open minded kind of guy and if I have indeed steered the thread than I should apologize for that, but I have read through every single post here and I'll be darned if I can find anywhere where I have steered it. I have done my best to keep if from turning into the same old argument that we have never seemed to settle in lots of other threads, but steer? Perhaps you would be good enough to point those bits out to me so that I can edit those parts. But then on another thread you accused posters of being anti diy and anti internet sales and again, I read the entire thread, each post and could find nothing of the sort in any of the posts. Are you perhaps confusing this forum with another?
Similar Threads: Need capacity/size
Forum Title Date
Water Softener Forum, problems, installation and r Need a manual for a 20 year old model 60 KINETICO Sep 9, 2014
Water Softener Forum, problems, installation and r Need help programming new Fleck SXT timer Jul 24, 2014
Water Softener Forum, problems, installation and r Need new whole-house water softener Jul 6, 2014
Water Softener Forum, problems, installation and r If I needed to repair my Fleck 7000 SXT, which has a plastic bypass on the valve... Jun 8, 2014
Water Softener Forum, problems, installation and r need softener advice Jun 3, 2014

Share This Page