From what I have read, I think a 24,000 grain is the correct size? I tested the hardness on a strip and it's about 4-5.

5 people x 75 gal x 4.5 hardness x 6 days between regen = 10,125

We do a lot of laundry and have two dishwashers, both are HE machines but still get above average usage, so I used 75 gal per day per person for my calc.

Actually with 24k size, it will be more like 15 days between regen. Is there a problem with that many days? From reading Alice's posts, the ideal is 6-7 days between regen.

Water pressure is excellent.

Also, hubby likes control, so I think the SXT is the option we will use. Electricity at site not a big issue. will make sure to get 10% cross linked resin since Im on city water, top basket and gravel bed.

Now just wondering which Fleck series to go with... And whats the benefit of a twin tank?

Thank you!

"5 people x 75 gal x 4.5 hardness x 6 days between regen = 10,125 ". Are you including a one day reserve in your calculations?

Before you decide on a size consider the SFR requirements.
24k is a 3/4 cube softener with only 7 gpm SFR.

Hi justalurker

Thanks for replying!

no I didnt include a reserve day. Current flow rate is 12+ gpm, so we want to try and maintain that. So then I guess we are looking at a 48k grain capacity?

Thank you!

A question about flow rate:

At the bath tub, our flow is 12+ gpm. But this is becuase there is no restrictor. All our other outlets are no where near that amount because of the water saving restrictors. And we rarely take baths. So should we still size to that rate?

Fleck, yes. Vortech... NO.

Hardness test strips are fine for general indication of hardness but not the way to determine correct softener sizing.

I do not recommend basing a decision on what treatment equipment and what size is required based on water authority reports that are two or three years old and not indicative of what the exact water conditions are at your location today. Doing that almost guarantees that you'll make the wrong choice.

In general one calculates for the maximum when considering water conditions and flow rate. There is constant SFR and peak SFR to consider. You can't just arbitrarily up-size because that can cause problems.

The hardness you used in your calculations (4.5 gpg) is slightly above the MINIMUM value reported by the city. MAXIMUM is 20 gpg. If you want to ensure you never see hard water, you size your softener for the maximum hardness.

If your water usage is actually in the 75 gallons/person/day range, that places you solidly in the 2.5 cubic ft softener size. Even at a more reasonable water usage rate of 60 gallons/person/day, 2.5 cubic ft is a good size for you. At that size softener, you will have plenty of available flow rate to serve your high-flow tub.

You may wish to contact the city and see how often you can expect the higher hardness. If it is hours, rather than days/weeks at a time, then you could size your softener a bit smaller. However, the safest way to go is still sizing for maximum hardness.

Lurker
Why the emphatic NO on the Vortech tank?

Alice
Thanks. Can you educate me in how you are determining that 2.5 cubic feet is the correct size? Is that based on flow? I see the softener cubic feet ratings are not exactly correlated to thei grain capacity rating. So should I think of it as buying a softener size which it "at least" 2.5 Cubic ft AND >42k grain capacity?

So 5 ppl x 60 gal x 20 hardness x 7 days of regen = 42,000 grain capacity

And at 2.5 cubic ft, that leaves me with the following:

Fleck 9000 twin tank 48k grain
Fleck 7000 sxt 80k grain
Fleck 5000 proflow sxt 80k grain
Fleck 2510 80k grain

is there any downside in oversizing the grain capacity?

Ooooh, Alice and Lurker....

Is the Vortech system the same as the "vortex" system Alice talks about here:

"Gravel underbed. The gravel underbed is there to set up proper flow patterns, improve backwash and prevent channeling. Many softener sales companies like to leave this out or sell softeners with a vortex system instead. Vortex systems weigh less than gravel so they cost less to ship. In addition, they are a more expensive item that adds profit for the softener salesperson, but provides no additional benefit to the homeowner . It simply adds another piece of equipment that can break. "

2.5 cubic ft (80,000 grain) size is determined by hardness of 20 gpg as reported by your water system. It would not be oversized. With any softener, you don't maintain the original capacity. In order to be salt-efficient, the resin is regenerated with a reasonable salt dosage, which reduces resin capacity.

Yes, Vortech is the same as my typo vortex - I failed to catch a spellchecker replacement word.

This post was edited by aliceinwonderland_id on Mon, Apr 7, 14 at 11:06

Deleted double-post.

This post was edited by aliceinwonderland_id on Mon, Apr 7, 14 at 15:22