AFWFilters Fleck 48K + Upflow Carbon Review
Verdict: The Fleck 5600SXT 48K softener paired with a separate upflow carbon tank. It ranks #2 in our best whole house water softener and filtration system list.
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| Grain capacity | 48,000 grains* |
|---|---|
| Max flow rate | 12 gpm* |
| Resin | 1.5 cu ft 10%* |
| Warranty | 5 yr valve, 10 yr tank* |
* From the seller's Amazon listing; not yet confirmed by the manufacturer.
Unmarked values come from AFWFilters's own pages or manuals; values marked * come from the Amazon listing (ASIN B07GRDYLDM). Model 56SXT-10% combo.
Check price on Amazon ($1,300+)Who the AFWFilters Fleck 48K + Upflow Carbon is for
Homes with room for a proper two-stage system.
Who should skip it
Small utility rooms.
Pros
- Separate carbon tank, so each stage can be serviced on its own
- Fleck valve
- Long tank warranty
Cons
- Top price band
- Three tanks' worth of floor space
- Few buyer reports
Our take
A separate carbon tank is the traditional, serviceable way to add filtration to a softener.
Upflow carbon tanks push water up through the bed, which keeps the carbon from packing down and channelling, so they need no backwash cycle of their own. That is why this pairing has no second control valve to maintain.
Plan floor space for three vessels: the carbon tank, the resin tank and the brine tank. Put the carbon first in line so chlorine is removed before it reaches the softener resin. If your city uses chloramine rather than chlorine, ask AFWFilters whether the carbon is catalytic; standard carbon removes chloramine much more slowly.
How it compares on paper
- Against the Kenmore Elite 520 Hybrid: more capacity (48,000* vs 31,000 grains) and a higher rated flow (12* vs 8* gpm).
- Against the GE Smart Softener with Filtration 30K: more capacity (48,000* vs 30,000* grains) and a higher rated flow (12* vs 8* gpm).
* Seller-listed value, not yet confirmed by the maker; unmarked values are from the manufacturer.
AFWFilters Fleck 48K + Upflow Carbon 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 AFWFilters Fleck 48K + Upflow Carbon 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: 5.3/10 (provisional)
| Capacity | 2.3 / 3 — 48,000 grains (64,000 = full marks) |
|---|---|
| Flow | 2.4 / 3 — 12 gpm (15 gpm = full marks) |
| Iron handling | 0 / 1.5 — no iron limit stated |
| Value | 0.6 / 2.5 — price band $1,300+ |
Alternatives to the AFWFilters Fleck 48K + Upflow Carbon
- Kenmore Elite 520 Hybrid (#1): One cabinet softens and filters.
- GE Smart Softener with Filtration 30K (#3): Smart alerts plus filtration.
- Aquasure Softener + RO Bundle (#4): Adds drinking-water RO.
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.