Another Water Softener Sizing Help Thread

[SAS]

Sorry for doing this when I see there are other sizing threads, but I'm struggling a bit to understand what variables do and don't count. Here are the basics:
Hardness: 25
Iron: .05
# of People: 4

Most on-line calculators tell me to go for a 48,000 grain unit, but a significant minority suggest 64,000. Two dealers whom I called (but who did not do any on-site testing) both insisted that the Fleck 5600 SXT 48,000 grain unit with 1.5 cubic feet of resin was more than sufficient. There is only a $40 difference between the two units, so I don't mind sizing up if it is in any way beneficial. I like the idea of regenerating less frequently, and a couple of times each year we have large family gatherings (4 kids, spouses, 4 grandkids) for about a week each time, so does that mean I should go for the larger softener? Also, I see that I have several tank choices. Let's say I go with the 64K. Should I get a 12 x 48, a 12 X 52, or a Turbinator 10 X 54?

Advice would be welcome.

 

[Reach4]

12 X 54 would be the popular choice for 2 ft[sup]3[/sup] of resin.
10" x 54" for 1.5 ft[sup]3[/sup] of resin.

 

[Sponsor]

 

[Mialynette2003]

First of all, with only .5 ppm iron you don't need a turbulator. Now lets see how the numbers look with a 2 CF. Your compensated hardness would be 30 GPG. With the family members using 65 gallons per person per day (65*30*4 people)= 7800 grains removed per day. 7800*7 days=54600 grains removed per week. With a 2 CF (64K) you would get 40K at the efficiency setting. so 40K-7800=32200/65/30/4= 4.1 days between regens.

Now lets see how the numbers look with a 1.5 CF. Your compensated hardness would be 30 GPG. With the family members using 65 gallons per person per day (65*30*4 people)= 7800 grains removed per day. 7800*7 days=54600 grains removed per week. With a 1.5 CF (48K) you would get 30K at the efficiency setting. so 30K-7800=22200/65/30/4= 2.8 days between regens.

I would recommend a 2 CF system.