Pre water softener filter recomendation and water softner optimization


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Old 03-11-13, 08:20 AM
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Pre water softener filter recomendation and water softner optimization

I just installed a Fleck 5600sxt water softener, 32000 grain capacity with c-100 resin. Here is my city water specifications:

Total Hardness: 110ppm (6.43gpg)
Iron: 0.046ppm (0.0027gpg)
Chloramine instead of free chlorine

I average about 4000 gallons of use per month. The first fundamental question I have which I can't seem to find a simple answer is to filter or not, and if so what kind of filter? I was going to do a canister filter (despite the fact I constantly read to avoid them like the plague), but I decided against it at the last minute.

Mainly I would like less hassle than changing filter elements all the time so I would like some sort of backwash filter. At that, I would prefer something I could run with a 5600 series valve since that is what my softener is and I am familiar with it.

So, here is my goals:
1) sediment is not a problem, but if there is something to do to help my softener resin might as well do it.
2) remove at least part of the chlorine and other items that KDF or carbon would normally remove before the softener.
3) verify dealer settings on the 5600sxt for optimum efficiency.

I have been watching this forum for quite a while and almost everyone is very knowledgeable here. Sometimes the threads even get entertaining.....


EDIT: forgot to add the link of one filter posibility
Fleck 5600 Auto Backwash ChemSorb Sediment Filter 1.5
 

Last edited by erfigge; 03-11-13 at 08:24 AM. Reason: Added filter link...
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Old 03-11-13, 08:51 AM
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1. Each ppm of iron equals 5 grains of compensated hardness (some say 3 or 4 compensated grains). If I were setting your softener up I would set it at 8 grains.

2. If you don't have a sediment problem you don't need a sediment filter. Cartridge sediment filters cause problems in most home installations because they are not properly maintained. The regeneration process of the softener will remove minor amounts of dirt/sediment that the softener may see. Sediment filters are only indicated where there are large amounts of sediment.

3. Cartridge filters should generally be avoided for whole house treatment.

4. If you decide you want to remove chloramines (and I don't recommend it) buy a separate backwashing GAC filter (2 cubic foot is a good size for most homes) and install it in front of the softener. While it costs more initially it will be much more effective than a cartridge type filter.
 
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Old 03-11-13, 09:23 AM
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So what you are saying is basically in my case you wouldn't recommend any type of filter in front of the softener? I know free chlorine is supposed to be bad on softener media, but maybe chloramines don't matter as much?

I also forgot to add the specific softener settings that was recommended to me (I have an 18" x 33" brine tank).

Hardness 7 (I will change this to 8)

15% safety factor reserve

Day override setting is 14. I have seen everything from 7 to 14, but I was told 14 by dealer. Is that ok?

Back wash time is 10 minutes
Brine draw time is 60 minutes
Rapid rinse time is 10 minutes
Brine fill time is 9 minutes
 
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Old 03-11-13, 09:53 AM
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Correct--From the information you provided I don't believe additional filtration is necessary. From an economic standpoint it is less expensive to simple replace the softener resin as necessary than to install and maintain a separate filter to remove chlorine. An appropriately sized carbon filter will need the media replaced typically twice as often as resin exposed to chlorine needs to be replaced.

Please provide the capacity setting (in grains) and the size of the drain line flow control (DLFC) if you want an evaluation of your settings. The DLFC size is typically listed on a sticker on the back of the valve.
 
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Old 03-11-13, 10:10 AM
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Sorry, thought I posted the size, but probably didn't. It is a 32,000 grain unit. The DLFC is 2.0 gpm.
 
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Old 03-11-13, 12:04 PM
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1. I need to know the capacity setting in the control--not the amount of resin.
2. I meant to ask for the brine line flow control (BLFC) --not the DLFC.
 
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Old 03-11-13, 12:27 PM
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Hmm, If I'm understanding correctly you set the capacity in the valve to match the capacity of the unit. I put in 1 CF of resin and programmed the control to 32. I attached a picture of the exact step (except for mine is set to 32).

As for the brine line flow control number, I will have to go look at that specifically when I get home.

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Old 03-11-13, 12:40 PM
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Hmm, If I'm understanding correctly you set the capacity in the valve to match the capacity of the unit. I put in 1 CF of resin and programmed the control to 32. I attached a picture of the exact step (except for mine is set to 32).
NO.

The capacity is variable, up to a maximum possible amount determined by the amount of resin. The capacity is determined by the salt dose.

In practice the maximum achievable capacity is 30,000 grains/cubic foot of resin and is achieved with a salt dose of 15 lbs/cubic foot. However a salt dose of 15 lbs/cubic foot is very salt inefficient. For typical household applications a maximum salt dose of 6-8 lbs/cubic foot is typically used and yields a capacity of 20,000 or 24,000 grains.
 
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Old 03-11-13, 01:42 PM
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Ah, a light bulb is finally going off. The BLFC is set to 0.5 gal/min. I knew there had to be some sort of actual control to the filling of the brine tank, not just how much water you happened to put in.

As for the capacity of the resin, I put in 1CF of this resin:

CATION-100-BOX Standard Mesh Cation Exchange Resin provides for economical softening capabilities of both household and commercial water softeners. Polymer Structure Polystyrene 8% cross linked with Divinylbenzene Physical Form and Appearance black spherical beads Whole Bead Count 90% Min. Functional Groups Polystyrene Sulfonate Ionic Form (as shipped) Na+ Mesh Size (U.S. Std.) 16-50 Moisture retention, Na+ form 45-50% Swelling, Na+->H+ 5% max. Total Capacity in sodium form 1.9 me/ml pH Range, Stability 0-14
So, it seems despite the claims as to what I was sold this is truly not a 32000 grain unit. Even at that I'm no where near needing that much anyway. For the settings, this is the only place I know of in the unit to set any sort of capacity. You set the hardness and the capacity in grains (x1000) unless I'm missing something.
 
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Old 03-11-13, 02:04 PM
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Hmm, my resin was not black, more of a brown or tan type color.
 
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Old 03-11-13, 02:35 PM
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A 1 cubic foot softener is commonly described as having a capacity of 32,000 grains. But to get that capacity a salt dose of 18 or more lbs/cubic foot must be used. In practice 15 lbs/cubic foot and 30,000 grains is the max.

With a BLFC of .5 gal/minute and 9 minutes brine fill you get 4.5 gallons of water added and at 3 lb/gallon of water that is a salt dose of 13.5 lbs. Assuming a BLFC of 0.5 gpm you would set the brine fill time to 4 minutes to get a salt dose of 6 lbs.

But--are you sure it is 0.5? Most units are shipped with a .125 or .25 gpm BLFC.

As I posted earlier a salt dose of 6-8 lbs is a good balance of salt efficiency and good performance with the capacity set based on the salt dose.
 
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Old 03-12-13, 09:09 AM
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Bob, I put my engineering degree to use last night and finally wrapped my head around the calculations.


The actual capacity of the unit really doesn't have anything to do with the "stated" capacity, so why would the dealer tell me to program that number in?

There is a saying that I maybe even read here, but I believe in it every day:
I believe in God, all others bring data!
So anyway, I put together a simple excel sheet last night to help me go through the calculations and then I had a thought that this could potentially be something useful to everyone else. It calculates the brine fill time ect, but I was wondering what the factors behind the back wash time, brine draw time and rapid rinse time that could be based upon the brine fill time.

Also, I did double check the BLFC on my 5600SXT and it is indeed 0.5 gal/min (1.5 lbsalt/min).Name:  IMG_0519.jpg
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Old 03-12-13, 09:52 AM
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but I was wondering what the factors behind the back wash time, brine draw time and rapid rinse time that could be based upon the brine fill time.
There is not a relationship between brine fill time and the other factors. If you think about it you will realize that, among other factors, brine fill time depends on the size of the BLFC and that can be an arbitrary choice.

Backwash time is determined primarily on how dirty the resin is--presence of iron and manganese require longer backwash times and applications with some silt may also require an increase in backwash time. You have relatively low levels of iron and manganese and 10 minutes should work well.

Brine draw and slow rinse is typically 60 minutes--that value works well over a fairly wide range of conditions.

Fast rinse, also called settling rinse, is there to firm up the resin bed and provide some additional removal of any remaining regenerate. You could reduce that to 5 minutes.
 
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Old 03-12-13, 10:51 AM
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Thanks for your help with this. Basically brine draw should almost always be 60 minutes. I don't mind a little bit longer rapid rinse just ensure any residue is removed.

Other than that, if you think this excel sheet would be handy for anyone else and there is anything to add do more correct it wouldn't take me much to put in. I know I haven't addressed maximum flow rate which is mostly a function of volume of resin.......

Would you agree with the 20% additional KCl needed over NaCl and the values in the chart?
 
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Old 03-12-13, 11:50 AM
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20% is a reasonable average estimate of the adjustment factor for KCl. But in practice it varies with salt dose and water conditions.

Generally the reserve factor is determined based on average daily use with a 1-1.5 day reserve factor. Also as a general rule a softener is set up to use the capacity less the reserve factor between each regeneration. Salt dose is adjusted to get an appropriate capacity. Regenerating once a week with little or no iron is considered a good design point with more frequent regeneration for higher amounts of iron is desirable.

My general point is that water conditions and salt and water economy should be taken into account.
 
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Old 03-12-13, 02:05 PM
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Ok, I finally realized I was kind of going about the dosing the wrong way. I could keep the same dosing schedule, but adjust the number of grains of capacity down by 20 percent.

So, I think I have settled for a 4lb/ft^3 dosage which would give me 12,160 grains of capacity. At my conditions I would run through that in approximately 11 days. I know the longer the resin bed sits without being back flushed it will become more prone to tracking. I have seen everywhere from no more than 6 days between regen to 14 days being ok. Any issue with 11 or 12 days between regen's as a worst case (since I don't have much iron) or should it be less than that?

I was reading deeper into Purolite's C100 data sheet and there are guidelines and specifications for amount of back flush time (and flow rate), rinse time ect and it mostly comes down to bed depth. But, I realized I needed to cut my nerdom off.......
 
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Old 03-12-13, 02:25 PM
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If you are reading the technical data then presumably you learned that hardness leakage varies inversely with salt dose. Some people notice the increased hardness leakage at low salt doses.

An additional consideration is that low salt doses don't do a great job at cleaning iron from the resin. While your iron levels are low the combination of longer times between regeneration and low salt dose may show in poor performance over time.

I suggest you use an iron cleaner regularly and monitor the performance. If use of iron cleaner isn't enough to get satisfactory performance then you may need to use a higher salt dose.
 
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Old 03-12-13, 03:20 PM
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If you are reading the technical data then presumably you learned that hardness leakage varies inversely with salt dose. Some people notice the increased hardness leakage at low salt doses.
I saw that. Short of the issue with iron, it basically comes down to the question of still getting soft water by day 10 or 11 or 12. Periodically I can monitor the hardness after the water with my pool testing kit and make slight adjustments over time to the dosage as need be. The nice thing is I tried to do this so I can see the impact from a cost stand point as well, even though that isn't the driving factor at the end of the day. I could even do a high salt dose regen every once and a while......

Thanks for all your help! I have a deeper understanding of water softeners than I probably ever wanted. hehe
 
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Old 02-17-14, 10:49 AM
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Any updates on this thread?
 
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Old 02-17-14, 11:08 AM
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My system has actually worked quite well. I have been very happy with the Fleck.

I did end up moving from the city to a rural water district just outside of town. The water comes from the same place, just chloramine in the city, chlorine on rural water. Once I moved I actually upped the salt dosage a little bit because the water doesn't feel as soft with chlorine, at least I don't think so. Chlorine is supposedly a little harder on the resin then chloramine so I upped the dosage for that reason as well.

Otherwise everything is working great. I have tweaked the spreadsheet a little bit, but it was a real help in at least getting a good starting point and seeing approximately what I would be spending with different settings.
 
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Old 06-18-14, 01:23 PM
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Spreadsheet

erfigge, you mentioned tweaking your spreadsheet. If the mods were at all significant, could you repost it? I am using it as a planning tool for my coming installation. Thanks for sharing your work!
 
 

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