Need a Water Softner! Which One?

Here is another perspective on SFR that is taken from another website:

I have a paper from Fleck that states as follows:

for Series 9000 Model KO-R-320 32,000 Grains 1.00 Cu. Ft. Mineral:

Peak flow is 19 GPM = 4309 Lit./Hr.

Continuous flow is 14 GPM = 3175

However, resin manufacterrurs define the continuous flow rate through 1 liter of cation resin as 40-42 Lit. of Water/Hr./ Lit. Of resin which brings us to only 5.24 GPM = 1188 Lit./Hr. for Model KO-R-320 32,000 Grains 1.00 Cu. Ft. Mineral.


Resin manufacturers are always more conservative than equipment manufactures. If you want the best possible results in almost all circumstances use the resin manufacturers specifications. Most of the time the equipment manufacturer's specs will work acceptably. I recently saw specs for a 2 cubic ft 13" softener at something like 40 gpm peak flow with a 1 1/2" valve. This seems way out of line to me. You might get the water through it but how soft would it be and how long would the resin last?


You have no mistake. The valve can handle that flow, butas you have correctly noticed the resin manufacturers specify usually about 5gpm per cubic foot. I have always used this rule and called it my rule of 5. A softener can handle slightly higher (peak flow) rates for a short time before hardness leakage will occur.
This is one of the biggest problems in the retail arena since Big Box companies and unscrupulous salespeople alike will not take this into true account when selling to larger families.
I can't tell you how many 3500 to 5000 square foot homes I have seen 3/4 and 1 inch valves on 1 cubic foot tanks installed. Many times reducing from 1 1/4" to 1 1/2" plumbing.
You calculation is more correct for sizing and will serve you and your customers much better for the long run.

There is a definite limit to how fast you can flow water through ion exchange resin. Flowing too fast will result in leakage of ions. You can exceed the resin manufacturers specifications but the quality of the water produced will not be as good. For softening if you flow too fast that will result in higher hardness leakage. Many equipment manufacturers do have high flow rates showing in their specifications for softeners. For residential applications that may not be a problem because most home owners are happy of the hardness of their water is less than 1.5 grains per gallon. That can usually be achieved even when flowing faster than twice the resin specification. However if you follow Jim Wark's recommendations above you will never go wrong.

For commercial/industrial applications it is always best to match the end user's flow rate to the resin manufacturer's flow rate. Most commercial/industrial end user's are sensitive to hardness leakage.

ibjamin said:

OK, I think I get it. Just throwing numbers out here. 1 cu ft of resin can hold 30K max. 10lbs of salt will get back 20K but to get the next 10K you have to use 15lbs. So you have to use more salt to get the entire 30K.

Or you can use a larger softner with more resin. So I would use roughly 24K of the 48K capacity of 1.5cu ft resin in 8 days. But when I regenerate, I only have to regenerate the 24K that was used and that puts me on the steep side of the salt efficientcy curve. So I use less salt, have higher SFR, and the extra capacity I might need in the future.

Sounds good. Thanks!

George

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It takes 15 lbs to get 30K/cuft of regular mesh resin. Nine lbs gets you 24K and 6lbs gets you 20K. In a 1.5 cuft 6lbs/cuft is 6*1.5=9lbs, gets you 30K. 15lbs*1.5=22.5lbs and 45K.

19gpm for 1 cubic?????????

was I sleeping in class that day?

Skip Wolverton said:

The formula I learned back in 1990 is 1 cubic foot of resin =
30,000 grains @ 15 lbs salt
20,000 grains @ 8 lbs salt (it is actually 6 lbs but you have to deduct a reserve so the 8 lbs salt has the reserve buildt in)

A 1 cf softener:

20k/17 gpg hardness = 1176 gal between regen
1176/2 people/75 gpd useage =7.8 days between regen
30 days in a month/7.8 = 3.8 regens per month
3.8 * 8 lbs salt per regen =30.76 lbs per month

A 1.5 cf softener:

30k/17 gpg hardness = 1764 gal between regen
1764/2 people/75 gpd useage =11.76 days between regen
30 days in a month/11.76 = 2.5 regens per month
2.5 * 12 lbs salt per regen =30 lbs per month

With iron in the water, the longer run between regens, the higher chance all the iron will not be rinsed off the resin. That means with a bigger unit, you may have to back down on the gallon count.

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Why would you use 30K in a 1.5 cuft when you only need 20K in this example?

In my 1.5 cuft I'd get 20K and a 1000 gals to keep with the suggested 'regenerate once every 7-9 days'. I'd use 5.1 lbs per regeneration, or 19.38 lbs per month. Or 1274 lbs saved over 10 years compared to your figures.

I've been doing it that way for many years and I have very satisfied customers.

Bob999 said:

Here is another perspective on SFR that is taken from another website:

I have a paper from Fleck that states as follows:

for Series 9000 Model KO-R-320 32,000 Grains 1.00 Cu. Ft. Mineral:

Peak flow is 19 GPM = 4309 Lit./Hr.

Continuous flow is 14 GPM = 3175

However, resin manufacterrurs define the continuous flow rate through 1 liter of cation resin as 40-42 Lit. of Water/Hr./ Lit. Of resin which brings us to only 5.24 GPM = 1188 Lit./Hr. for Model KO-R-320 32,000 Grains 1.00 Cu. Ft. Mineral.

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Those figures are at a 15 psi pressure drop across the softner. The control valve and softener have different SFR figures. Resin manufacturers state the SFR gpm of 1 cuft of their resin. That is the figure that dictates/controls the constant SFR of a softener. The resin manufacturers' SFR for their resins are very conservative because they are set for commercial/industrial softeners where leakage in ppm or mg/l is very critical. That means residential softeners using the same resin get a much higher constant SFR gpm because residential softeners deal with gpg (grains per gallon) which is 17.1 ppm or mg/l. The WQA says 1 gpg in the softened water is the goal for residential, I say 0 gpg.

Bob999 said:

Resin manufacturers are always more conservative than equipment manufactures. If you want the best possible results in almost all circumstances use the resin manufacturers specifications. Most of the time the equipment manufacturer's specs will work acceptably. I recently saw specs for a 2 cubic ft 13" softener at something like 40 gpm peak flow with a 1 1/2" valve. This seems way out of line to me. You might get the water through it but how soft would it be and how long would the resin last?

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Using the resin manufacturers' figures for residential softeners will cause you to over size softeners which leads to channeling of the bed and hardness leakage. The only cure for that is to prematurely (manually) regenerate the softener.

The volume of resin in the tank dictates what size tank can be used for a given cuft volume of resin. The SFR of the control valve tells dealers/manufacturers what size tank the control valve can service. The cuft of resin also dictates the constant SFR gpm of the whole softener.

The Fleck 5600 can service a 12" (2.0 cuft) tank/softener. The Clack WS-1 up to a 21" (7.5 cuft) tank/softener.

It is all a fine dance on the head of a pin.

Sizing the resin for both a good flow rate, cap. taking in the numbers iron, mn, hardness...

To little and the higher the psi drop, to much and channeling ...

If Iron is in the mix, then to long and iron and resin get to know each other TO WELL.... and that is not good.

Some of this is in the books and some of it is what one has found out the hard way..

Water temp also comes into play in what kind of flow rates one can get, how much Iron one can remove with a softener, along with the flow rate for the backwash.

This question is for Gary Slusser and Akpsdvan.

What constitutes an oversized softener which leads to channeling? What are the parameters of an oversized softener which leads to channeling?

Most literature charaterizes softener size either on the basis of flow per cubic foot of resin or flow per square foot of tank size. Residential flow rates are variable--from a gallon or two per minute for a single faucet to ?? depending upon the number of fixtures and size of piping. So how does one determine when a softener is oversized?

Bob999 said:

This question is for Gary Slusser and Akpsdvan.

What constitutes an oversized softener which leads to channeling? What are the parameters of an oversized softener which leads to channeling?

Most literature charaterizes softener size either on the basis of flow per cubic foot of resin or flow per square foot of tank size. Residential flow rates are variable--from a gallon or two per minute for a single faucet to ?? depending upon the number of fixtures and size of piping. So how does one determine when a softener is oversized?

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Say a 2 bath house that has a flow rate of no more than 10gpm because of a large tube. If one then puts in 3 cubic foot unit, there is every chance that there is going to be channeling going on. The water is going to be looking for the path with no to the least resistance, thus channeling and it will happen more if the flow rate is down around 1-2 gpm

Here is one for you, years ago the State of Alaska told a community home owner association that they needed 120pgm, after putting a digital meter in place and monitoring it different times of the day for a month the best that was seen was 20gpm so they where able to go with some thing in the middle 65gpm.

Channeling is not just for the down flow, but also for the backwash. To much media could also lead to channeling on the backwash if the gpm is not there for the lifting of the media.

Bob999 said:

This question is for Gary Slusser and Akpsdvan.

What constitutes an oversized softener which leads to channeling? What are the parameters of an oversized softener which leads to channeling?

Most literature charaterizes softener size either on the basis of flow per cubic foot of resin or flow per square foot of tank size. Residential flow rates are variable--from a gallon or two per minute for a single faucet to ?? depending upon the number of fixtures and size of piping. So how does one determine when a softener is oversized?

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What Akpsdvan said.

It comes down to an accurate educated guess. The key is determining peak demand gpm. Then using hard figures for your constant SFR gpm for the volume of resin that just exceeds the peak demand gpm.

Going over the peak too far would get you into channeling IF there were sufficient small flows like a home office or other full time daily use with lots of toilet flushes, rinsing dishes or glasses of water, ice making, an RO etc..

'nother water softener sizing question.

We have an old softener that's on its last legs. As a reasonably handy homeowner I'm looking to replace it. I looked at Gary's web site for sizing but the numbers I'm getting are... odd. Can someone double-check these for me?

1) Hardness. I live in Madison, WI, and the water reports for the municipal water are:
Hardness - 17gpg
Iron - 0.20 ppm
Manganese - 14 ppb; I assume that's 0.014 ppm?

So that would give an adjusted hardness of (17) + (2*0.2) + (4*.014) ~ 17.5 ~ 18 grains, right?

2) Water usage. From our water bill we use 178 gallons per day, so that's 178 * 18 = 3,204 grains per day, and over 8 days that's 25,600 grains. Now some of that water is unsoftened, but would we want a 24k or 32k capacity?

3) Resin tank size. We have two baths, two kitchens (a 2-flat), one dishwasher, and one front-loading (so theoretically low flow) clothes washer. From the 1997 UPC (which Madison follows) I get an estimated 17 gpm, which seems high. This is from:
2x bathtubs = 8.0 wsfu
2x lavatories = 2.0 wsfu
2x HET = 5.0 wsfu
2x kitchen sink = 3.0 wsfu
1x dishwasher = 1.5 wsfu
1x clothes washer = 4.0 wsfu
1x hose bibb - unsoftened = 0.0 wsfu
Total = 23.5 wsfu ~ 17.0 gpm

I take it those numbers are assuming some average use. We rarely use the tubs and have low-flow showerheads; also, a front-loading washer. Do either of those affect the flow rate?

Anyway, as an exercise, if I use the numbers as given I get the following:

Resin: 2.5 ft^3 for 17gpm SFR

But using the hardness/salt calculation as given on Gary's site I get 1.5 ft^3 for ~30k grains of hardness.

So which would we use? 1.5 or 2.5 ft^3?

Thanks!

... as a note, if you misread the water report as manganese in parts per million instead of parts per billion, you get _really_ hard water.

17gpm if every thing was on at the same time... chance of that ?

I would go with the 1.5 cubic foot unit , 10gpm with a peak if needed it could get to the 17 with a pressure drop of 25psi....

17 grains is getting up there, I have a few around here that are in the 20's or low 30's...

Just my thoughts on the matter

What I have seen from my customers with iron is that if the run time (days between regens) is too long, they get a iron colored water right after a regen. I would reccommend a 32k unit and regen every 6 days @ 8# salt vs every 8 days @ 12# Salt.

abernat said:

'nother water softener sizing question.

We have an old softener that's on its last legs. As a reasonably handy homeowner I'm looking to replace it. I looked at Gary's web site for sizing but the numbers I'm getting are... odd. Can someone double-check these for me?

1) Hardness. I live in Madison, WI, and the water reports for the municipal water are:
Hardness - 17gpg
Iron - 0.20 ppm
Manganese - 14 ppb; I assume that's 0.014 ppm?

So that would give an adjusted hardness of (17) + (2*0.2) + (4*.014) ~ 17.5 ~ 18 grains, right?

2) Water usage. From our water bill we use 178 gallons per day, so that's 178 * 18 = 3,204 grains per day, and over 8 days that's 25,600 grains. Now some of that water is unsoftened, but would we want a 24k or 32k capacity?

3) Resin tank size. We have two baths, two kitchens (a 2-flat), one dishwasher, and one front-loading (so theoretically low flow) clothes washer. From the 1997 UPC (which Madison follows) I get an estimated 17 gpm, which seems high. This is from:
2x bathtubs = 8.0 wsfu
2x lavatories = 2.0 wsfu
2x HET = 5.0 wsfu
2x kitchen sink = 3.0 wsfu
1x dishwasher = 1.5 wsfu
1x clothes washer = 4.0 wsfu
1x hose bibb - unsoftened = 0.0 wsfu
Total = 23.5 wsfu ~ 17.0 gpm

I take it those numbers are assuming some average use. We rarely use the tubs and have low-flow showerheads; also, a front-loading washer. Do either of those affect the flow rate?

Anyway, as an exercise, if I use the numbers as given I get the following:

Resin: 2.5 ft^3 for 17gpm SFR

But using the hardness/salt calculation as given on Gary's site I get 1.5 ft^3 for ~30k grains of hardness.

So which would we use? 1.5 or 2.5 ft^3?

Thanks!

... as a note, if you misread the water report as manganese in parts per million instead of parts per billion, you get _really_ hard water.

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You are confusing things. There are two parts to sizing a softener correctly.

1. The regenerated capacity/salt use efficiency stated in K grains and lbs of salt used per regeneration.

2. The constant SFR gpm of the softener's volume of resin which must be greater than the maximum peak demand flow rate gpm run through the softener.

For number 1... all softeners have an adjustable K of capacity because they all allow setting a varied amount of salt used per regeneration. To get 30K in a 1 cuft of regular mesh resin you need a 15 lb salt dose per regeneration. In a 1.5 cuft you get 30K with only 9 lbs; 6 lbs less per regeneration; or a max of 45 K with 22.5 lbs..

I. E. Skip here says "a 32K" (1.0 cuft/9 gpm constant SFR) but then he is not setting the salt dose to be able to regenerate 30K... at 8 lbs he won't get 24K in real life. And, he is going to get you into a regeneration at 6 days instead of 8 days so he'll cost you (365/6 and 8) 61-46= 15 more regenerations per year. That will use substantially more city water that you pay for and more salt. His 6 days @ 8 lbs* 61= 488 lbs/yr - 46* 8.5= 391/yr or 97 lbs more and if I did it you'd save 46* 8=368 so 488-368= 120lbs saved. Times say 10 yrs and that is literally over a half ton of salt saved.

For number 2... you say you need 17 gpm (I'd have to go over that with you because that is higher than you need for 2 bathrooms because you're using the code which is done as if you have water running at every fixture in the house all at once, and no one lives like that, and I don't size like that) so by code you'd need a 2.5 cuft softener because it has an 18 gpm constant SFR.

That is not the SFR of the softener at X psi pressure loss.

That is the max gpm the resin can remove all the hardness from and the gpm @ 15 psi pressure loss you would get many more gpm through the softener but, the water will not be 0 gpg soft; there will be some hardness left in it. That hardness is called hardness leakage, and no one should buy a softener that isn't going to constantly remove all their hardness. Nothing but the cuft volume of resin controls that SFR.

So... once you know the peak demand gpm of the house, then you select the cuft volume of resin to provide the constant SFR needed which sets the cuft size, then you set the salt dose lbs to cover the K of capacity you need for a regeneration on average once every 7-9 days.

Your softener doesn't have be that large (2.5 cuft/18gpm SFR) and you only need 27K of capacity. So... 9 lbs in a 1.5 cuft gets you 30K and you would set the lbs at 8.5 lbs for 27K (with 12 gpm constant SFR) or go to a 2.0 cuft and set it at 27K @ 8 lbs. and get a constant SFR of 13 gpm.

Skip Wolverton said:

What I have seen from my customers with iron is that if the run time (days between regens) is too long, they get a iron colored water right after a regen. I would reccommend a 32k unit and regen every 6 days @ 8# salt vs every 8 days @ 12# Salt.

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That's because you sell a mechanical metered Fleck 5600 that does not allow you to change the length of minutes that your backwash, rapid rinse and final rinse run for.

Gary Slusser said:

That's because you sell a mechanical metered Fleck 5600 that does not allow you to change the length of minutes that your backwash, rapid rinse and final rinse run for.

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That's because I see the control boards lasting an average of 4 years. Had a service call Fri that the board had to be replaced. It was only 6 years old.

Finally got my softener installed and up and running... I can tell the difference in water, nothing like a clean shave in the morning with soft water... The instruction were super detailed... My only recommendation is to merge all of the pictures and text file of instructions into a pdf file so everything is all wrapped up in order in a nice need tidy file (I work in the technology field, LOL)... Picked up some of the super iron out Gary recommended for the softener and started cleaning up fixtures the washer and toilets around the house.. Man that stuff works great, if there were only a way of running that stuff through all the house plumbing easily to clean it out... Had my first regen the other night and everything went perfectly..

Skip Wolverton said:

That's because I see the control boards lasting an average of 4 years. Had a service call Fri that the board had to be replaced. It was only 6 years old.

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That's because you work on Kenmore and other big box brand cabinet models.

I've sold over 1300 Clack valves and had 8-9 circuit board problems in 6 yrs; since Jan 21 2004. They have been installed indoors and outdoors all over the US and Canada, including Alaska and one or two in Puerto Rico.

Mr G is correct on the Kenmore, GE, Polor Star control boards, there must be some thing like a kill switch in there that after x years it goes out...

There are some Fleck and Clack Control boards that are 8+ years old a still going strong.

Part of any Digital control challenge is Humidity, if where that board is at has more humidity in the air, it may not last as long.

Gary Slusser said:

That's because you work on Kenmore and other big box brand cabinet models.

I've sold over 1300 Clack valves and had 8-9 circuit board problems in 6 yrs; since Jan 21 2004. They have been installed indoors and outdoors all over the US and Canada, including Alaska and one or two in Puerto Rico.

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I've worked on them all. All of them, Fleck, Autotrol. Eco, Sears, Culligan and Clack. I'm just saying I've seen control boards give out on the average of every 4 years.

Gary Slusser said:

So... once you know the peak demand gpm of the house, then you select the cuft volume of resin to provide the constant SFR needed which sets the cuft size, then you set the salt dose lbs to cover the K of capacity you need for a regeneration on average once every 7-9 days.

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Ahh... I see. So instead of the code (which has us running two tubs + sinks + toilets + washing machine... all at once) I want to go with what actually can happen and then possibly round up a bit. That makes a lot of sense. Thanks!