Compare Aquasure Harmony vs Fleck 5600SXT
Aquasure Harmony 48K vs Fleck 5600SXT Budget Kit or Certified Valve
The Aquasure is the cheapest softener we track at $629.99 for 48,000 grains. The Fleck 5600SXT costs $876 for 1.0 cu ft, and WQA lists Pentair's configuration with a certified flow.
Where to buy · Aquasure Harmony: $629.99 on the seller's site, checked Oct 22, 2026. No retailer link yet.
Where to buy · Fleck 5600SXT: $876.00 (1.0 cu ft) on the seller's site, checked Oct 22, 2026. No retailer link yet.
Short answer: Choose the Aquasure for the lowest price on city water, if you’ll register it for the 5-year warranty. Choose the Fleck for a certified flow, a standard valve and a longer warranty out of the box.
Capacity by Salt Dose
Aquasure Harmony
No capacity-by-dose table published. Rated 48,000 grains at an unstated dose.
Fleck 5600SXT
No capacity-by-dose table published. Rated 35,000 grains at an unstated dose.
Certification Side by Side
| Aquasure Harmony | Fleck 5600SXT | |
|---|---|---|
| Status | No listing found | WQA listed |
| Certifier and standard | – | WQA NSF/ANSI 44 |
| Certified flow | not certified | 10.8 gpm (5600 SXT-1.0) |
| Salt efficiency | not published | not published |
| Sold as | 48,000 grains | 35,000 grains |
| At lowest published dose | not published | not published |
Specs Side by Side
| Aquasure Harmony | Fleck 5600SXT | |
|---|---|---|
| Service flow (maker) | not yet verified | 10 gpm peak (1.0 cu ft kit) source |
| Valve flow | Valve alone: 20 gpm continuous at 15 psi drop, 26 gpm peak source | not yet verified |
| Resin | not yet verified | 1.0 cu ft (also 0.75, 1.5, 2.0) source |
| Pressure | 20–125 psi source | not yet verified |
| Warranty | 1 year; 5 years if registered within 60 days; resin excluded with iron, manganese or chlorine source | 5-year valve, 10-year tank source |
| Price | $629.99 source | $876.00 (1.0 cu ft) source |
Where They Differ
Price. $629.99 vs $876 (1.0 cu ft) or $1,010 (1.5 cu ft), on the sellers’ sites.
Certification. None found for Aquasure. WQA lists Pentair’s 5600SXT-1.0 at 10.8 gpm, efficiency rated.
Warranty. Aquasure: 1 year, or 5 if you register within 60 days. Fleck kit: 5-year valve, 10-year tank.
Common Questions
Is the Aquasure's 20 gpm real?
It’s the control valve alone: 20 gpm continuous at a 15 psi drop, 26 gpm peak. The full system’s flow isn’t published or certified.
How much salt will either use?
Neither publishes capacity at each salt dose. Both let you set the dose, and lower doses use salt more efficiently. See grain capacity and salt dose.
Full sheets: Aquasure Harmony · Fleck 5600SXT. Or size your own in the calculator.