Advice - sizing for efficiency (SFR vs. capacity)

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Mikha'el

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Hello - new here. And new to water softening... Seattle ---> Austin, TX.

Getting ready to DIY a system, and would like to get some advice on sizing.
Already read many of the sizing posts here, but a sanity check would be appreciated.

Municipal supply (city info says they use chloramine)
13 gpg hardness (according to Hach 5B test)
0 iron
2 adults, 2 young children
Probably on the low side of usage, <60 gallons/days/person
2.5 bath, kitchen sink/dw/clothes washer
Main tub filler test says about 10gpm (may be changing it out to an <8gpm rated faucet)
Outside hose bibs are ahead of the supply shut-off

Based on the sizing info/calculators I've tried, it would appear that I should size for 12+gpm SFR, ignoring capacity.
This puts me into a 2.0 ft3/64k unit, if my math is correct.
Assuming 15 day regeneration cycle, 8lb/ft3 salt?

There's already a 3/4" softener loop, looks like it might be reduced from a 1" supply. Flow and pressure are fine as-is, though I will probably want to install a filter ahead of the softener for chlorine. Not sure if restoring the 1" line would provide any benefit.

Am I spot-on with the 2.0 unit, or would I be better off for efficiency with a 1.5?
Considering a Fleck 5600SXT valve at this point.

Any/all help and suggestions appreciated!
Michael
 
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Reach4

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You actually had your tub spout tested as putting out 10 GPM? I am not sure about the SFR choice. http://www.qualitywaterassociates.com/softeners/sizingchart.htm somehow shows a minimal SFR improvement going from 1.5 to 2 cuft yet it shows a bigger increase from 2 to 2.5.

However you will have better salt efficiency with either 2 cuft or 1.5 cuft and going to 6, 5 or even 4 pounds of salt per cuft instead of 8 pound/cuft demand driven with maybe a 21 day override. Because you have chlorinated water, you don't have iron.

From a pure efficiency point of view, the 2 cuft will use slightly less salt because it will not leave unused reserve capacity as often -- presuming that your reserve is set as an amount rather than a percentage.
 
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ditttohead

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Chlorine removal ahead of the softener is fine but do not use a Big Blue Filter, use a backwashing system. If space is a consideration, a stacked tank design would be far better then a BB style carbon filter.

Post a picture of the plumbing. If the loop has been modified from 1" to 3/4", then restore it to 1". The cost is minimal to do it correctly.

Looking at your numbers, I would recommend a 2 CF system, you could go slightly smaller but why? The cost of doing it slightly larger is reasonable and the gain in efficiency is nice. It also allows you to do a lower salt setting that will be even more efficient.
 

Mikha'el

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You actually had your tub spout tested as putting out 10 GPM? I am not sure about the SFR choice. http://www.qualitywaterassociates.com/softeners/sizingchart.htm somehow shows a minimal SFR improvement going from 1.5 to 2 cuft yet it shows a bigger increase from 2 to 2.5.

However you will have better salt efficiency with either 2 cuft or 1.5 cuft and going to 6, 5 or even 4 pounds of salt per cuft instead of 8 pound/cuft demand driven with maybe a 21 day override. Because you have chlorinated water, you don't have iron.

Hi, thanks for the replies, gents...

It's a Moen two-handle "roman tub faucet" and really puts out a lot of water at full whack. I filled a 5 gallon bucket in around 30 seconds. As mentioned, I might swap it out with a less "robust" unit. :)

I wasn't sure if regenerating every 15+ days was a good idea, thought every 7-8 was supposed to be ideal. But if it's not an issue I'll go with the 2.0.
 

ditttohead

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Regeneration frequency is not as critical as some may lead you to believe. I would recommend no less than every 30 days if possible. If you have iron or other contaminants that can foul resin, frequent regenerations are critical.
 

Mikha'el

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Post a picture of the plumbing. If the loop has been modified from 1" to 3/4", then restore it to 1". The cost is minimal to do it correctly.
Here it is... valve is 3/4" - as I mentioned, flow/pressure are fine now, but if there's a good reason to change it, OK.
I'll probably get a REAL plumber to do the rework... my soldering skills on old copper are nil.

(not pictured - Kenmore 70 softener - not in service - that came with the 25 year-old house.)
photo.JPG
 

Lifespeed

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Naw, change it to 1" fittings and use a 7000SXT valve with 32 mm internal manifold. Tiny price increase, get the flow you're plumbed for.
 

ditttohead

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From a purely technical standpoint, it is unlikely that the flow rate would be noticed, but... why not change it? It would sure look a lot nicer to replumb that with all 1" and maybe use the 1" stainless flex lines and be sure the system has 32mm riser.
 

Mikha'el

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From a purely technical standpoint, it is unlikely that the flow rate would be noticed, but... why not change it? It would sure look a lot nicer to replumb that with all 1" and maybe use the 1" stainless flex lines and be sure the system has 32mm riser.
Oh, hey, missed these last few posts (thanks, guys). Just installed the softener last weekend, after having the loop re-plumbed with a 1" 3-valve bypass.

Got the softener up and running - it's doing the job, but I'll be digging into the programming soon (came "programmed" from the dealer) to make sure it's set for best efficiency.

BTW - I did get the 7000sxt 32mm, 2.0 cuft + 1" Falcon stainless flex. Looks real purty. :)
 
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Lifespeed

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Looks nice. I think you will notice the 1" piping combined with the 7000SXT large valve with 32mm distributor tube.
 
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