DuraWater Fleck 9100SXT Twin Review
Verdict: A twin-tank softener on the Fleck 9100SXT valve: one tank regenerates while the other keeps supplying soft water. It ranks #10 in our best water softener systems list.
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| Grain capacity | 48,000 per tank* |
|---|---|
| Control valve | Fleck 9100SXT metered, twin alternating* |
| Resin tank | 10 x 54 in x2* |
| Resin | 1.5 cu ft per tank* |
* From the seller's Amazon listing; not yet confirmed by the manufacturer.
Unmarked values come from DuraWater's own pages or manuals; values marked * come from the Amazon listing (ASIN B00YB586K6). Model 9100SXT 48K twin.
Check price on Amazon ($1,300+)Who the DuraWater Fleck 9100SXT Twin is for
Large or shift-working households that use water at night, and homes with very hard water.
Who should skip it
Anyone happy with a 2 a.m. regeneration.
Pros
- Soft water around the clock, no regeneration downtime
- Fleck valve parts are widely available
- Metered, on-demand regeneration
Cons
- Top price band
- Needs space for two resin tanks plus a brine tank
- Overkill for most two-person homes
Our take
A single-tank softener has to take itself offline to regenerate, usually overnight. The 9100SXT alternates between two tanks, so there's never a window of hard water.
Twin tanks also let you size each tank smaller for the same effective capacity, because one tank is always fresh. That is useful on very hard water, where a single tank would regenerate every few days.
The 9100SXT is a metered valve that switches tanks by gallons used, not by clock, so regeneration happens when one tank is exhausted, even mid-afternoon. Make sure the drain and brine line can handle a regeneration at any time of day.
DuraWater Fleck 9100SXT Twin sizing at a glance
Using the 48,000-grain capacity from the seller listing, here is roughly how many days it runs between regenerations. At 12 gpg, a family of four would regenerate the DuraWater Fleck 9100SXT Twin about every 10 days, and two people on 18 gpg water about every 14 days; aim for 5–8.
| Household | 8 gpg | 12 gpg | 18 gpg | 25 gpg |
|---|---|---|---|---|
| 2 people | 32 | 21 | 14 | 10 |
| 4 people | 16 | 10 | 7 | 5 |
| 6 people | 10 | 7 | 4 | 3 |
Spec score: 2.9/10 (provisional)
| Capacity | 2.3 / 3 — 48,000 grains (64,000 = full marks) |
|---|---|
| Flow | 0 / 3 — not stated |
| Iron handling | 0 / 1.5 — no iron limit stated |
| Value | 0.6 / 2.5 — price band $1,300+ |
What buyers report
Summarised from Amazon buyer reviews; not our own testing.
- Mostly positive comments on quality and reliability.
- Mixed comments on installation: some buyers are happy, others report problems.
Alternatives to the DuraWater Fleck 9100SXT Twin
- Aquasana SimplySoft 40K (#1): Only softener here certified to NSF/ANSI 44; highest rated flow among cabinet units.
- AFWFilters Fleck 5600SXT 48K (#2): Most serviceable valve; chlorine-tolerant 10% resin.
- Aquasure Harmony 48K (#3): Most capacity per dollar with a pre-filter included.
- Tier1 48K (#4): Lowest price band for a full-size 48K.
See all our picks in the best water softener rankings, the top three on our best home water softener systems page, or every spec side by side in the water softener comparison table, or more from Fleck. Not sure about size? Use the calculator in our water softener buying guide.
Before you buy: how a water softener works, what water softener installation involves, the full cost of running a softener and the maintenance it needs. On a private well? See our water softener for well water picks.