Water Softener Sizing

Old 02-15-16, 06:05 AM
Thread Starter
Join Date: Feb 2016
Posts: 2
Received 0 Votes on 0 Posts
Water Softener Sizing

Hey Folks,

I am new to the softener world and trying to come up to speed pretty quick. I have been doing a lot of reading through the forum, etc... Anyways... We bought the house we're in last year and the water hardness has consistently measured 15gpg. I am preparing to purchase a new softener, most likely a Fleck 5600sxt and just wanted to get some opinions on the correct size for efficiency.

We have the following to go by:
7 people in the house (Hopefully to drop lower in the next year or two as some finish college...)
2 Bathrooms
Hardness - 15gpg
Well Water with sediment filter after well pump
No iron issues
3/4 piping

I was originally thinking about a 5600sxt - 48,000 grain, however, before I purchase, after looking at the calculator I saw here on the forum, I might be better off with the 5600sxt - 64,000.

Can someone give some insight here to what the more efficient size would be to help keep salt purchases to a minimum down the road?

Thanks for any input!
Old 02-15-16, 12:45 PM
Join Date: Dec 2002
Location: Houston, TX
Posts: 151
Received 0 Votes on 0 Posts
I used to assume that the softener capacity listed by manufacturer is "the golden number" that you can use to figure out which softener to buy. However, I learned that it is not the listed capacity but what's important is how much resin media is in the softener.

If you operate softener at listed capacity, your salt consumption will be very high. Read these articles to get better understanding of how to arrive at proper sizing:

Understanding True Water Softener Capacity - Aquatell
How to Properly Size a Water Softener - Aquatell

Hope that helps.
Old 02-15-16, 02:12 PM
Thread Starter
Join Date: Feb 2016
Posts: 2
Received 0 Votes on 0 Posts
The Fleck 64K Setup I am looking at has 2 Cubic feet of resin. Based on this, I think I have calculated the settings here for both the 6lb and 8lb salt usage. The 6lb setting would be approximately 12lbs per regeneration and the 8lb setting would be approximately 16lbs per regeneration. I would still go with the 64k unit to allow for some overhead if we had guests or missed a regeneration due to usage. I know there is a little tradeoff between the 6lb and 8lb. The 6lb setting obviously uses less salt, but possibly a little more water from what I understand. The 8lb setting used slightly more salt, but uses a little less water from I understand. I have used both 60 and 75 gallons per day as calculations for our family of 7. I know there are some other variables that might cause this to vary some, but Iím still in the basic learning mode.

7 People x 60 Gallons x 15gpg = 6300 Grains

7 Day Regeneration = 44100 Grains (8lb Setup @ 48K) x 52 regenerations = 832lbs = 21 bags x $6 per bag = $126 per year

6 day Regeneration = 37800 Grains (6lb Setup @ 40K) x 61 regenerations = 732lbs = 19 bags x $6 per bag = $114 per year

7 people x 75 Gallons x 15gpg = 7875 Grains

6 Day Regeneration = 47250 Grains (8lb Setup @ 48K) x 61 regenerations = 976lbs = 25 bags x $6 per bag = $150 per year

5 Day Regeneration = 39375 Grains (6lb Setup @ 40K) x 73 regenerations = 876lbs = 22 bags x $6 per bag = $132 per year

Thanks for the input!

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: