There is no simple formula, as there are many "variables" that must be considered when "setting" a water softener valve regeneration frequency.
First is the "quality" of the water you are treating, and then amount of water to be used ( number of people in household ),
What is the hardness level of your water before any filters? ( grains per gallon or ppm )
What is the iron level ( if any ) of your water before any filters? ( ppm = Parts Per Million )
What is the pH level of your water from the source ( before any filters )?
How many people use the water in your home?
And the last variable is the CAPACITY or Amount of RESINS in the media tank.
Common Tank Sizes and Amount of Resins Inside
8" x 35" 0.64 cu. ft. ( 20,480 grains )
8" x 44" 0.75 cu. ft. ( 24,000 grains )
9" x 35" 0.75 cu. ft. ( 24,000 grains )
9" x 40" 1.00 cu.ft. ( 32,000 grains )
9" x 48" 1.00 cu. ft. ( 32,000 grains )
10" x 35" 1.00 cu. ft.( 32,000 grains )
10" x 40" 1.00 cu .ft. ( 32,000 grains )
10" x 44" 1.25 cu. ft. ( 40,000 grains )
10" x 54" 1.50 cu. ft. ( 48,0000 grains )
12" x 52" 2.00 cu. ft. ( 64,0000 grains )
13" x 54" 2.50 cu. ft. ( 80,000 grains )
Then, it's a question of whether your valve is a simple "day timer" ( operating on the days you "SET" ), or a metered "demand" timer, that counts and tracks the amount of water used.
For an example of the "math" or calculations of "capacity" between regenerations, I'd refer you to this article about how to figure the gallons setting on the mechanical FLECK Metered valves,
How to Set Meter Program Gallons
And the last thing that matters somewhat is the amount of SALT used with each Regeneration,
****The amount of salt needed is mostly based on the amount of resins being recharged.
3/4 cu.ft. resin = 6 - 9 lbs.
1 cu.ft. resin = 8 - 10 lbs.
1.5 cu.ft resin = 12 - 15 lbs.
9 lbs for 8 - 9 inch diameter resin tanks,
and 12 lbs. of salt for 10" tanks is average.
If there is a lot of iron ( over 2 ppm ) or if the water is really hard ( over 30 grains ),
then an extra 2 - 4 lbs. of salt per regeneration should be used.
COMMON Frequency of Regeneration
A typical residential system will use 6 - 12 lbs of salt per regeneration at least once a week.
Very hard water ( over 30 grains ), or water high in iron ( over 1 ppm ), may require regenerating every 2 or 3 days.
The result is you will be using at least 30 - 40 lbs. of salt, and more common you will be using 60 - 100 lbs. of salt per month.
P.S. If you run out of Salt, don't expect to have soft water after a few days.
And it may take more than one regeneration to get the water feeling soft again once you've added salt.
I recommend keeping the salt level above the water level in your Brine Tank.
When you start seeing the water level ( normally between 8 - 12 inches ) then it's time to think about adding more salt ( 40 - 120 lbs. ).
Here is a photo of a "Starved" Brine tank ( only a few Pellet "crums" under lots of water ).
You want the water to be covered by the salt, not the other way around.
|Understanding Water Softener Capacity|
A Brief Excerpt from our Clack Seminar
Cation Exchange Water Softeners have a Maximum Hardness Removal Capacity, depending on the amount of Softening Resin which has been loaded into the Mineral Tank, and the amount of SALT used during each Regeneration.
Increasing the amount of Salt (Brine) used to Regenerate the Resin Bed, will increase the amount of Capacity Recovered, per cubic foot of Resin, but will Decrease the Efficiency of the Water Softener.
Variable (Brine) Dosages for a 9X48 - One Cubic Foot Water Softener
In the programming of the control valve you can check the “Brine Tank Refill” time setting or the “LBS of Salt” setting, to be sure you have the proper Salt Dosage programmed into the control valve.
- 3 Lbs. of salt will dissolve into 1 gallon of water.
- Regenerating @ 15 lbs. SALT per Cubic Foot of Resin will yield 30,000 grains capacity.
- 15 Lbs. of salt will require the softener control valve to fill the brine tank with 5 gallons of water.
- Equal to 2133 grains per lb. of SALT
- Regenerating @ 10 lbs. SALT per Cubic Foot of Resin will yield 27,000 grains capacity.
- 10 Lbs. of salt will require the softener control valve to fill the brine tank with
3-1/3 Gallons Of Water.
- Equal to 2700 grains per lb. of SALT
- Regenerating @ 8 lbs. SALT per Cubic Foot of Resin will yield 24,000 grains capacity.
- 8 Lbs. of salt will require the softener control valve to fill the brine tank with 2-2/3 gallons of water.
- Equal to 3000 grains per lb. of SALT
- Regenerating @ 6 lbs. SALT per Cubic Foot of Resin will yield 20,000 grains capacity.
- 6 Lbs. of salt will require the softener control valve to fill the brine tank with 2 gallons of water.
- Equal to 3333 grains per lb. of SALT
Be sure the proper Injector is installed in the control valve. To verify the correct injector for the system size, refer to the attached Clack Valve Injector Chart.
Be sure the proper Drain Line Flow Control Button (DLFC) is installed in the control valve and that the button is installed in the correct orientation, the rounded bevel edge is facing the water flow from the control valve to the drain.