Water Softener Sizing

[bcx]

I'm a bit confused about water softener sizing. I followed the water sizing calculation here:

http://www.qualitywatertreatment.com/water_softener_sizing.htm

2 people x 75 gals x 9 gpg + 0.0 iron = 1350 grains per day, which they recommend a 24000 grain capacity.

So I figured a unit with 0.75 cubic feet of resin would suffice. When I go Aquatell's product page for the Fleck 5600 SXT - 24000 grain, it says "a good choice for a home with hardness less than 5 grains per gallon. If your hardness is higher than this, you really need a bigger softener."

So is this true? I'm not sure what size I should be getting.

 

[Reach4]

Read http://www.qualitywaterassociates.com/softeners/sizingchart.htm and continue with the link at the bottom.

If your eyes glaze over, try skipping ahead to the link at the bottom.

 

[Sponsor]

 

[ditttohead]

House size is another important item to consider. Pipe size, flow rates, fixture counts etc.

All that being said, a larger softener is usually a good idea, you can set them much more efficiently and they do not cost much more than a porrly sized, or undersized system. I would recommend a 1.5 Cu. Ft. system, it cost almost the same and is 50% larger. Set for extreme efficiency, you will go about 15-20 days between regenerations, and if you have guests over you will have plenty of capacity. The larger systems also flow more water nad have lower pressure drops, as well as last longer since they are working less.

 

[bcx]

Thanks for the link Reach. So it looks 1 is the minimum cubic foot size for my softener (although I don't think the calculator is precise enough to get to 0.66 or 0.75)

Based on the information you entered, 1350 is your Daily Grains of Capacity needed. 10800 is the Total Grains of Capacity you need for approximately once per week regeneration with a 24 hr reserve. 1 is the minimum cubic foot size of softener required for your capacity needs.

Some more info: I have 3/4" copper pipes, washing machine, dishwasher, 2.5 baths with one having dual shower heads.

 

[ditttohead]

The 50% increase in system size over the 1 CF is worth the very minor increase in cost. You will also have less pressure loss with the larger system.

 

[Bannerman]

With water softeners, there is actually more than one capacity that needs to be considered. While total capacity is most often referenced on charts, utilizing the full capacity will require an excessive amount of salt to regenerate. As resin is fully exhausted, regeneration requires 15 pounds of salt to regenerate 30,000 grains capacity for each 1 cu/ft of resin.

When regeneration is programmed to occur when only a portion of the total is exhausted, salt efficiency will increase considerably. In addition, a larger capacity softener will support higher gallon per minute flows before the softening capacity is exceeded and hardness bleeds through to the faucets.

In support to Dittohead's recommendation, up-sizing to a 1.5 cu/ft unit (48K grains total) would permit a high salt efficiency setting while also supporting up to 12 GPM flow rate and an infrequent regeneration requirement. As mentioned, if you frequently entertain guests or your family increases in number, you have plenty of capacity without overtaxing or needing to reprogram or upgrade the softener.

Using your calculated current requirement of 1350 grains/day, a 1.5 cu/ft softener set for 30K grains of usable capacity, would require regeneration approx every 22 days using 9 lbs/salt = efficiency of 3,333 grains per pound of salt @ 6 lbs salt/cu/ft.

A 1cu/ft softener would require 8 lbs of salt every 17 days to regenerate 24,000 grains = 3,000 grains/lb @ 8 lbs/cu/ft.

A 3/4 cu/ft softener would require 11.25 lbs every 16 days to regenerate only 22,500 grains = 2,000 grains/lb @ 15 lbs/cu/ft.

While smaller units may also be programmed to be more salt efficient, their usable capacity will further decrease while the frequency of regeneration will need to increase, thereby requiring more wear and tear and more water to regenerate.

As there is likely little cost difference in up-sizing to a 1.5 cu/ft unit, it would make the most sense to obtain a unit which is salt efficient while also meeting your current and future needs without concern of restriction.

 

[bcx]

Thanks everyone for their input. I'll guess I'll be considering the usual suspects, between the Fleck 5600, Clack WS1, and Autotrol 255.

 

[ditttohead]

You cant go wrong with any of those units. Any would be an excellent choice!

I would recommend the USA made mineral and brine tanks.

 

[bcx]

Well I picked up the Clack WS-1 48000 grain. This thing is a lot larger than I thought. When I picked it up the guy at the store said I must have pretty hard water (>20 gpg). Since mine is only 9 gpg I'm wondering if this is overkill.

 

[Reach4]

Better overkill than under, and besides, the bigger tank will allow a bigger flow while softening. Since you don't have iron, it is OK to go up to 30 days between regenerations. Set your softener up for 6 pounds of salt per cubic ft. That means that you will want your brine fill to add 3 gallons (9 pounds of salt) each time. Set the capacity to 30000 grains.

 

[bcx]

Thanks for the tips. I'll try out those settings after I've installed it this week.

 

[Michael Burke]

I don't know if I need to start a new thread, but I am also confused about the proper size I should be getting. I've been to about 3 different calculators and each one gives me different sizes I should be looking to get. I have 3.5 bathrooms consisting of 3 showers, 1 jacuzzi tub thats rarely used for the moment, 2 regular tubs, 6 faucets, and 4 toilets. Currently we have just 2 people in the house, then I read you factor half a person for washer and again for dishwasher. The home was built in 2005 and is about 2400sqft. I went to http://www.qualitywaterassociates.com/sizing.php and put in 17 for my water hardness, 3 people, and at 60/gal per person per day its telling me 24480 grains and 1.5 cuft softener. But I go to another site with a much simpler sizing chart and it says 40,000 grains and another says 64,000 since it says 75gal per person per day. The current softener we have (North Star NSC30UD1) seems to have died and it was only 34,300 grains according to the manufacturer. I was looking at the Fleck 7000sxt from http://www.qualitywaterforless.com/ProductDetails.asp?ProductCode=F-R48-70SXT but I am just so confused by all the different places giving different sizes I don't know what to purchase now. I want a system that has room for growth in the future like possibly a kid or two. Any help would be appreciated!

 

[Reach4]

I want a system that has room for growth in the future like possibly a kid or two. Any help would be appreciated!

City water or well? If a well, what is your iron level. Any water problems besides hardness? If chlorinated city water, going bigger is not a problem in that you can let it go longer between regenerations. You can save salt by using less salt per cubic ft of resin, but you might want to go with more salt use in a smaller unit when the usage grows. 10% crosslinked resin is often recommended as more durable for chlorinated water.

While plumbing, you might want to consider whether to run an unsoftened line for some drinking depending on your well's (or city's) water. You might want to consider a whole house filter for sediment that might come in.

 

[Tom Sawyer]

The variables make exacting calculations impossible. I'd go with a 2.0 cu/ft

 

[Michael Burke]

Las Vegas city water system, and this is their water report https://www.lvvwd.com/assets/pdf/wqreport.pdf. They state the hardness is 17, the lead is average 2 ppb which is 0.002 ppm. The house is already plumbed for a water softener as my current North Star NSC30UD1 has been in the house since it was built in 2005. So I should not be concerned with getting the http://www.qualitywaterforless.com/Fleck_7000SXT_Meter_64000_p/f-r64-70sxt.htm since my iron is essentially non-existent? Is that a reputable place to get this system since I know every place puts different things together and the valve is the actual Fleck part?

 

[ditttohead]

I don't recommend making a major purchase from a UPS store.

 

[Michael Burke]

.

 

[justaHO]

Ditto what Ditto said. A reputable dealer will pay in benefits back to you.