This
chart will help you to choose a water softener size that
is right for your needs. You will need to know the number
of people in your household and the grains of hardness per
gallon in your water. If you need a quick and easy hardness
testing kit, go to our Water Test
Kit page.
| Hardness
in Grains per Gallon |
Number
of People in Family +1* |
| |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
0-10 |
24k |
24k |
24k |
32k |
32k |
32k |
40k |
40k |
| 11-20 |
24k |
24k |
32k |
32k |
40k |
40k |
40k |
48k |
| 21-30 |
32k |
32k |
40k |
40k |
48k |
48k |
48k |
64k |
| 31-40 |
40k |
40k |
48k |
48k |
48k |
64k |
64k |
80k |
| 41-50 |
64k |
64k |
80k |
80k |
80k |
96k |
96k |
110k |
| 51-75 |
64k |
80k |
80k |
96k |
96k |
110k |
110k |
110k |
76-100 |
80k |
80k |
96k |
96k |
110k |
110k |
110k |
110k |
This
reference guide is based on every 4th night regeneration.
*Additional
person compensates for water using appliances.
Formula
for sizing softeners
Capacity
= No. of People x Hardness x 70 Gallons x Days Between Regeneration
Ex:
A family has 4 people with 33 grains per gallon hardness
with no iron.
4
+ 1(for appliances) x 33 Grains/Gal. x 70 Gallons x 4 Days
= 46,200 Grains. In this example, 46,200 grains of capacity
is needed on average every 4 days. Because no iron is present,
the low salt setting can be used. Select the softener that
will provide more than 46,200 grains at the low salt setting.
A
water softener will remove clear water iron (iron in solution).
When removing iron with a softener, compensate the hardness
by a factor of 5 grains per gallon for every part per million
of iron.
Ex:
A family has 3 people with 22 grains per gallon hardness
and 3 parts per million iron.
3
+ 1(for appliances) x 37 Grains/Gal. x 70 Gallons x 2 Days
= 20,720 Grains. In this example, 20,720 grains of capacity
is needed on average every 2 days. With iron present, the
softener should regenerate every other night and use the
medium salt setting. Select the softener that will provide
more than 21,000 grains at the medium salt setting.
