Systems Fleck 5600SXT
Fleck 5600SXT (US Water Systems)
The Fleck 5600SXT is the most common DIY softener valve. WQA lists Pentair's own 5600SXT configurations to NSF/ANSI 44 (10.8 gpm for the 1.0 cu ft system, efficiency rated). US Water Systems sells kits from $799.
Key specs at a glance
Sold as
35,000 grains
Salt dose not published
At efficient salt
not published
No capacity-by-dose table
Salt efficiency
not published
No grains-per-pound figure
Service flow
10.8 gpm (5600 SXT-1.0) WQA
Maker: 10 gpm peak (1.0 cu ft kit)
Max hardness
not published
Price
$876.00 (1.0 cu ft)
Seller's store price, checked Oct 22
Where to buy · Fleck 5600SXT: $876.00 (1.0 cu ft) on the seller's site, checked Oct 22, 2026. No retailer link yet.
Capacity by Salt Dose
No capacity-by-dose table published. Fleck gives the 35,000-grain rating without the salt dose behind it. Softeners in our database that do publish one deliver well under half their top figure at the lowest dose. Why that matters.
Sizes
| Model | Grains (maker) | Flow (maker) | WQA-listed flow | Store price |
|---|---|---|---|---|
| 0.75 cu ft | 26,000 | 7 gpm peak | 9.9 gpm | $799.00 |
| 1.0 cu ft | 35,000 | 10 gpm peak | 10.8 gpm | $876.00 |
| 1.5 cu ft | 53,000 | 15 gpm peak | 11.1 gpm | $1,010.00 |
| 2.0 cu ft | 70,000 | 20 gpm peak | 12.5 gpm | $1,045.00 |
Our Read
The 5600SXT shows up in almost every r/WaterTreatment thread because parts are everywhere and any plumber can service it. Pentair’s configurations are on the WQA list with flow figures, and the efficiency flag is set. The retailer’s 35,000-grain-per-cubic-foot figure is generous compared with published resin curves, so plan with less.Bottom line: The repairable, long-life DIY choice. You program the salt dose yourself, so size the resin for about a 7-day interval at a moderate dose rather than on the 35,000 figure.
Maker Claims vs the Record
35,000 grains "max capacity (new)" for 1.0 cu ft. US Water Systems product page
No salt dose given. Published resin curves elsewhere put 1 cu ft at 30,000 grains at 10 lb/cu ft and 15,000 at 3 lb (Neo-Pure data sheet).
35,000 per cubic foot is above most published resin curves. Size on about 30,000 at a high dose, less at an efficient one.
Kit built on the Fleck 5600SXT. US Water Systems product page
WQA lists Pentair's 5600 SXT-1.0 at 10.8 gpm, efficiency rated. WQA listing (Pentair Fleck)
The valve platform is certified in Pentair's configurations. The retailer kit itself isn't listed.
Certification Record
| Status | WQA listed |
|---|---|
| Certifier | WQA |
| Standard | NSF/ANSI 44 |
| What it covers | Hardness reduction, efficiency rated (DIR); not California-efficiency listed |
| Certified service flow | 10.8 gpm (5600 SXT-1.0) |
| Record | WQA listing (Pentair Fleck) |
The listing covers Pentair's 5600 SXT configurations. A retailer kit matches it only if the seller builds it to the listed configuration, which US Water Systems doesn't state.
Specifications
Performance
- Service flow
- 10 gpm peak (1.0 cu ft kit) US Water Systems product pagechecked 2026-10-22
- Resin
- 1.0 cu ft (also 0.75, 1.5, 2.0) US Water Systems product pagechecked 2026-10-22
Water and install limits
- Resin tank
- 9 × 48 in. (1.0 cu ft) US Water Systems product pagechecked 2026-10-22
- Brine
- 15 × 17 × 36 in. brine tank US Water Systems product pagechecked 2026-10-22
Warranty and price
- Warranty
- 5-year valve, 10-year tank US Water Systems product pagechecked 2026-10-22
- Price
- $876.00 (1.0 cu ft) US Water Systems product pagechecked 2026-10-22
What We Couldn't Verify
- Resin crosslink and the salt setting the kit ships with.
- Performance in your home, which depends on your water chemistry and use. We haven't tested this system ourselves.
Compare: Aquasure Harmony vs Fleck 5600SXT · Fleck 5600SXT vs WHES40
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Run your numbers in the sizing and salt calculator, or see the best water softeners.