Fleck and "Grain Capacity"

[KenJr]

Can anyone help me out here and explain to me the significance of 'grain capacity' on a Fleck softener?

I have a 4400 sq/ft house with 2 water heaters and 5 bathrooms (4 showers). I have 3 kids so we use a decent amount of water when you factor in dishwashing, laundry, etc...

I'm looking at the 120,000 grain...well, because it's the biggest...but would consider moving down a notch or two if it's enough to run my house.

Looking at the specs I see a slight difference in GPM and the volume of the salt tanks when comparing the 96,000 and 120,000 grain units.

Should I just go with the big one to be safe?

 

[Reach4]

Start with http://www.qualitywaterassociates.com/softeners/sizingchart.htm and continue with the calculator link at the bottom of the page.

You will need the hardness of your water too. Get the Hach 5B test kit and/or get a water test that includes hardness. If you get your water from a water company or town, they can tell you the hardness.

 

[Sponsor]

 

[KenJr]

I checked my city report (have a tester on the way to back that up) and they show 10.75 grains/gallon in their most recent report.

I'm using the softener sizing chart here: http://www.discountwatersofteners.com/sizing-chart

And for a family of 5 and anticipating a bit higher usage given 3 kids, laundry, etc... it's still telling me I could get away with a 40,000 grain system.

Is this possible? Initially I was just looking at the highest possible...then after some inital research was thinking a 96,000 and now the calc is telling me I could go as low as 40,000?

How about 80,000 and split the difference?

I've been trying to read up on how to best calculate with all the variables and such and realize that a 96,000 would definitely get the job done and would handle any high usage scenarios that might come up. But, looking to get the right system sized and not overbuy if not necessary.

Thanks so much in advance!

 

[Reach4]

I would go with a "64000" which is code for 2 cubic ft. That still gives you extra margin.

It will regenerate around every 12 days using 6 lb/cuft (= 12 pounds ) of salt.

 

[KenJr]

Thanks man. One final question. When I'm ordering the 7000 off the web one of the options is the plumbing connection. The default is 3/4" Noryl Male NPT. My loop is 1" copper pipe. Do I want to choose the 1" Noryl Male NPT option so that the hardware on the softener mates up nicely with the 1" on the loop?

 

[Reach4]

1 inch would be the better choice. As an amateur, I would connect to that with flex lines if it is permitted. https://terrylove.com/forums/index.php?threads/softener-connections.50749/
https://terrylove.com/forums/index.php?threads/connecting-softener-to-copper.59476/
https://terrylove.com/forums/index.php?threads/water-softener-install-with-pex-plumbing.46949/

 

[Bannerman]

I would go with a "64000" which is code for 2 cubic ft. That still gives you extra margin.

It will regenerate around every 12 days using 6 lb/cuft (= 12 pounds ) of salt.

To clarify Reach4's recommendation, a 2 cu/ft softener (64,000 total grains capacity) programmed to regenerate with 6lbs of salt per cu/ft of resin (12 lbs total salt), will provide 40,000 grains of usable capacity. This then supports the advice you were given of 40,000 grains meeting/exceeding your family's needs.

If your requirements should ever increase (ie: more people), the unit could be easily programmed to regenerate with 8/lbs of salt per cu/ft of resin which would then increase the usable capacity to 48,000 grains.


Edited to add 'The Math'

5 people X 11 grains per gallon X 60 Gal/day average consumption = 3300 grains/day required
40,000 grains usable / 3300 = (12.12) 12 days between regenerations which is great.


The chart you linked at Discount Water Softeners, estimates 75 gal/day/person which with the efficient appliances and fixtures available today, maybe too generous.
5 people X 11gpg X 75 Gal/day = 4125 grains/day
40,000 / 4125 = (9.69) 9 days between regeneration which remains good as it is less than 1X per week, but regeneration will likely occur closer to the 12 day interval.

Property irrigation is not calculated within the water volume as grass and other vegetation should be watered with the raw water before the softener.