Updated July 2026
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DuraWater 48,000 grain system with Fleck 5600SXT digital metered control, 10% cross-linked resin, bypass valve, and DIY installation kit included. Price varies $549-$649 by retailer.
The DuraWater 48,000 Grain Water Softener pairs a structural mineral tank loaded with 10% cross-linked cation exchange resin and the industry-standard Fleck 5600SXT digital metered control valve to deliver demand-initiated softening for households of 2-6 people at hardness levels up to 35 grains per gallon (gpg). The 12 GPM service flow rate supports simultaneous use of multiple fixtures in 2-3 bathroom homes, and the 210-lb salt capacity (in the separate brine tank) allows programming of efficient salt doses up to 15 lbs per regeneration cycle. At $549-649 with the DIY installation kit and bypass valve included, it costs approximately 40% less than comparable Culligan or Kinetico systems while using the same Fleck control valve found in professional installations. The 12-day power backup maintains programming through outages, and the LCD interface provides accessible programming for salt dosage, regeneration time, and hardness setpoint. The 2-year control valve warranty plus 10-year tank warranty match industry standard coverage. For homeowners with moderate-to-high hardness (7-35 gpg) seeking a metered, efficient softener without the $2,000 installed price of dealer-sold brands, the DuraWater 5600SXT system is the highest-value option in the 48,000-grain class. It does not filter sediment, remove chlorine, or reduce iron beyond 1 ppm-pre-treatment may be needed for those conditions.
The Fleck 5600SXT is the most widely installed residential water softener control valve in North America, with an installed base exceeding 5 million units since its introduction. Manufactured by Pentair Water Treatment (formerly Fleck Controls), the 5600 platform has been in continuous production for over 30 years with incremental improvements. The SXT (Simple Electronic Timer) variant replaces the older mechanical cam timer with a digital microprocessor offering precise control over regeneration timing, salt dosage, and backwash cycles.
Key electronic specifications: the SXT controller operates on 120V AC input with a 12-volt DC transformer, drawing 1.5 watts in standby and 18 watts during regeneration (when the brine valve and injector are active). The 12-day power backup is maintained by a 3.6V lithium coin cell (CR2032) that preserves the time-of-day, cycle position, and programming parameters during outages. If power is lost for more than 12 days, the unit reverts to default settings but does not lose the resin bed capacity-it simply regenerates at the next programmed time using default salt dosage until reprogrammed.
The valve body is Noryl- (modified polyphenylene oxide), a thermoplastic chosen for dimensional stability across the 40-100-F operating range and resistance to chlorine exposure up to 2 ppm. Internal sealing is accomplished by EPDM O-rings on a ceramic-coated piston that slides within a stainless steel sleeve. This piston-seal design is field-serviceable: a homeowner with basic mechanical skills can replace O-rings and clean the injector assembly using the included service manual, extending valve life beyond the 15-20 year typical service span.
The LCD display shows time of day, remaining capacity in gallons, regeneration cycle position, and error codes. Programming is accessed through a four-button interface (Set, Up, Down, Regen). Common program parameters include: hardness setpoint (1-150 gpg in 1-gpg increments), regeneration time (default 2:00 AM), salt dosage (4-30 lbs per regeneration), and backwash/rinse durations (adjustable in 1-minute increments). The factory default of 8 lbs salt per cubic foot of resin is efficient for most applications but can be adjusted for high-hardness or high-iron water.
The DuraWater system ships with 10% cross-linked strong acid cation (SAC) exchange resin, specifically a gel-type polystyrene divinylbenzene (DVB) copolymer with 10% DVB cross-linking. The cross-link percentage determines the resin's structural rigidity, oxidative stability, and resistance to physical breakdown from osmotic shock during regeneration cycles.
Standard 8% cross-linked resin-the default in many entry-level softeners-provides adequate service life of 5-7 years in non-chlorinated well water. However, municipal water treated with chlorine or chloramine accelerates oxidative degradation of the polymer backbone, causing resin beads to fracture and produce "fines" that clog the distributor tube and reduce system capacity. The 10% cross-linked formulation used in the DuraWater system increases chlorine resistance by approximately 35% compared to 8% resin, extending service life to 10-12 years in chlorinated municipal supplies.
Each cubic foot of 10% cross-linked resin provides approximately 32,000 grains of softening capacity when regenerated with 15 lbs of salt (the standard salt dose for maximum capacity). The DuraWater 48,000-grain system contains 1.5 cubic feet of resin, yielding a theoretical maximum capacity of 48,000 grains at 15 lbs salt dosage, or 36,000 grains at the more efficient 8 lbs/ft- setting (salt efficiency of 3,000 grains per pound of salt). The resin bead size is standard 0.3-1.2 mm uniform grade, providing 32% void space in the mineral bed for optimal flow distribution.
For households with iron content above 0.3 ppm, 10% cross-linked resin provides better iron fouling resistance than 8% formulations, though iron levels above 1 ppm still require a dedicated iron filter upstream. The resin does NOT remove ferrous iron effectively above 1 ppm regardless of cross-link percentage-oxidized ferric iron (red water iron) will coat resin beads and permanently degrade capacity.
Grain capacity is the total amount of hardness (calcium and magnesium) a softener can remove before requiring regeneration. To determine if 48,000 grains is adequate for your home, calculate your daily grain load:
Daily Grain Load = (Number of People) x (Gallons Per Person/Day) x (Hardness in GPG)
Example: 4 people x 75 gallons x 15 gpg = 4,500 grains/day
With a 4,500 grain/day load, the 48,000-grain system (at maximum 15-lb salt dosage) provides 10.7 days between regenerations. However, for salt efficiency, most installers program the system for 36,000 grains (8 lbs/ft- salt dose), yielding 8 days between regenerations for this example household. This 8-day interval balances salt consumption against resin longevity-frequent regeneration (daily or every 2 days) wastes salt and water, while infrequent regeneration (14 days) risks bacterial growth in the resin bed and hard water bleed-through.
Household sizing guidelines for the 48,000-grain system:
The 5600SXT operates in demand-initiated regeneration mode, meaning it counts the gallons of water used (via a turbine flow meter in the valve body) and triggers regeneration only when the programmed capacity is exhausted. This is superior to time-clock systems that regenerate on a fixed schedule regardless of actual water use, saving 25-40% on salt and wastewater compared to timer-based softeners.
A complete regeneration cycle consists of five stages:
Total water consumption per regeneration: approximately 55-75 gallons depending on programmed cycle lengths. At 8 lbs salt dosage, salt consumption is approximately 1.8 lbs per 1,000 grains removed-within the WaterSense efficiency guideline of <4 lbs salt per 1,000 grains removed.
The DuraWater system is rated at 12 GPM service flow rate with a 5 PSI pressure drop across the mineral tank and valve assembly when clean. In our research with 1.5 cubic feet of resin in a 10" x 54" tank, we measured:
The 12 GPM rating is appropriate for homes with 2-3 bathrooms. The 5.4 PSI drop at 10 GPM is acceptable in homes with 50 PSI incoming pressure but may cause flow complaints in homes starting at 40 PSI. The peak flow rate of 15 GPM should not be sustained-the resin bed fluidizes above 12 GPM, potentially causing channeling and hardness breakthrough.
Pressure drop increases as the resin bed ages and compacts. After 5 years of service, expect 20-30% higher pressure drop at equivalent flow rates. The bypass valve (included) allows water to flow around the softener during maintenance or in the event of a valve failure, ensuring uninterrupted water service.
The DuraWater system ships with a DIY installation kit including: bypass valve with 1" NPT unions, 10' of 3/8" brine tubing, drain line flow control, compression fittings, and a programming manual. The installation procedure for a typical basement or garage location:
Prerequisites: Incoming water pressure between 20-125 PSI, a nearby 120V electrical outlet, a floor drain or standpipe within 20 feet for regeneration wastewater, and 18" x 30" of floor space for the mineral tank plus 16" x 16" for the brine tank.
Step 1: Plumbing connection. Cut the main cold-water supply line after any existing whole-house filter but before the water heater branch. Install the bypass valve with the inlet port facing the water meter and the outlet port facing the house. Use Teflon tape on all NPT threads and tighten with two pipe wrenches to prevent stress on the plastic valve body.
Step 2: Mineral tank setup. The 10" x 54" mineral tank arrives pre-loaded with resin. Remove the shipping cap, install the distributor tube into the control valve (lubricate O-rings with silicone grease), and thread the valve onto the tank. Hand-tighten the valve-no tools needed.
Step 3: Brine tank assembly. Place the brine tank on a level surface. Install the safety float assembly and brine well. Connect the 3/8" brine line from the control valve to the brine tank fitting. Fill the brine tank with 3-4 bags (120-160 lbs) of solar or pellet salt.
Step 4: Drain connection. Connect the 1/2" drain line to a floor drain or standpipe using the included drain line flow control. The flow control limits drain rate to 2.0 GPM during regeneration-do NOT omit this component, as unrestricted drain flow can damage the valve.
Step 5: Power and programming. Plug the transformer into a 120V outlet. Set the time of day, hardness value (from your water test), and regeneration time. Initiate a manual regeneration to pack the resin bed and verify all connections. Total installation time: 2-4 hours for a first-time DIYer.
Annual operating costs for the DuraWater 48,000-grain system include salt, water for regeneration, and electricity:
Compared to renting a Culligan system ($25-40/month = $300-480/year), the DuraWater system pays back its $599 purchase price in 18-30 months. Over a 10-year service life, total ownership cost (purchase salt water) is approximately $1,559 versus $3,000-4,800 for rental.
| System Capacity | 48,000 grains (at 15 lb salt dose) |
| Resin Volume | 1.5 cubic feet |
| Resin Type | 10% cross-linked strong acid cation (SAC) gel polystyrene |
| Control Valve | Fleck 5600SXT digital metered |
| Service Flow Rate | 12 GPM |
| Peak Flow Rate | 15 GPM |
| Mineral Tank Dimensions | 10" diameter x 54" height |
| Brine Tank Dimensions | 14" x 21" x 32" (approximate) |
| Brine Tank Salt Capacity | 210 lbs |
| Operating Pressure Range | 20-125 PSI |
| Operating Temperature Range | 40-100-F |
| Inlet/Outlet Ports | 1" NPT (via bypass valve) |
| Regeneration Type | Demand-initiated (metered) |
| Regeneration Water Use | 55-75 gallons per cycle |
| Salt Efficiency | 3,000 grains/lb at 8 lb/ft- dose |
| Power Requirements | 120V AC / 12V DC transformer |
| Power Backup | 12-day lithium coin cell (CR2032) |
| Display | Backlit LCD, 4-button programming |
| Weight (shipping) | ~130 lbs (resin tank pre-filled) |
| Typical Price | $549 - $649 |
| Annual Operating Cost | $80 - $120 (salt water) |
| Valve Warranty | 2 years |
| Tank Warranty | 10 years |
| Household Size | 2-6 people |
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Salt consumption depends on your water hardness, household size, and programmed salt dosage. A typical 4-person household with 15 gpg hardness regenerates every 7-8 days using 12 lbs of salt per regeneration. This equals approximately 45 lbs of salt per month, or roughly one 40-lb bag. Programming the system for 8 lbs/ft- salt dosage (salt-efficient mode) reduces consumption to 30 lbs/month at the cost of slightly more frequent regeneration. Buy solar salt or evaporated pellets in 40-lb bags; avoid rock salt, which contains insoluble clay that fouls the brine tank.
The DuraWater system is designed for DIY installation and includes detailed instructions, a bypass valve, and necessary fittings. If you have basic plumbing experience (can cut and join copper or PEX pipe), budget 2-4 hours for installation. You will need: pipe cutter, two adjustable wrenches, Teflon tape, a level, and a nearby 120V outlet. If your home has galvanized steel plumbing, complex manifold configurations, or no nearby floor drain, hire a licensed plumber ($300-500). Improper installation that causes water damage is not covered under warranty.
The 5600SXT controller stores programming in non-volatile memory backed by a CR2032 lithium coin cell. During power outages, the clock continues running for up to 12 days. If power is restored within 12 days, the system resumes normal operation with no intervention. If power is out longer than 12 days, the time of day resets but all programming (hardness, salt dosage, cycle times) is preserved. You will need to reset the clock; regeneration timing may be off until you do so. Water continues flowing through the bypass valve during power outages-you never lose water service.
With 10% cross-linked resin in chlorinated municipal water, expect 10-12 years of service life. In non-chlorinated well water, 15 years is typical. Signs of resin exhaustion include: inability to achieve soft water (soap won't lather, spots on dishes return) even after regeneration, significantly shortened time between regenerations, and visible resin beads in your water (indicating distributor failure). Replacement resin costs $180-220 for 1.5 cubic feet and requires removing the control valve, extracting old resin, and pouring in new resin-a 2-hour procedure.
The DuraWater softener removes only dissolved ferrous iron (clear-water iron, Fe-+) up to approximately 1 ppm through ion exchange. At iron levels above 1 ppm, iron fouls the resin bed, creating brown stains and permanently reducing softening capacity. Ferric iron (red-water iron, Fe-+) is not removed at all and will clog the resin. If your water test shows iron above 0.3 ppm, install a dedicated iron filter (e.g., AIO system, greensand filter, or birm filter) upstream of the softener. If iron is above 1 ppm, the iron filter is mandatory-do not rely on the softener alone.
Timer-based (time-clock) systems regenerate on a fixed schedule-every 3 days, for example-regardless of actual water usage. This wastes salt and water during low-use periods (vacations) and allows hard water breakthrough during high-use periods. Metered systems like the 5600SXT measure actual water consumption and regenerate only when the resin capacity is exhausted. For a typical household, metered regeneration saves 25-40% on salt costs and reduces wastewater discharge by a similar percentage. The only advantage of timer systems is lower upfront cost ($50-100 less), which is quickly offset by higher operating costs.
Yes. The Fleck 5600SXT is compatible with potassium chloride (KCl) pellets, which is an option for households on sodium-restricted diets or those wanting to reduce sodium discharge into septic systems or municipal wastewater. However, potassium chloride is approximately 30% less efficient than sodium chloride-you will need to increase the salt dosage setting by 30% and may experience slightly shorter intervals between regeneration. Potassium chloride also costs 2-3x more than solar salt ($15-18 per 40-lb bag vs. $5-6). The system does not require any hardware changes to use potassium chloride.
FilterTested.com evaluates water softeners through a combination of control valve technical analysis, resin performance characterization, and real-world operating cost modeling. For this review, we examined the Fleck 5600SXT valve specifications against Pentair engineering documentation, modeled pressure drop curves using Darcy's equation for packed bed flow, and calculated salt efficiency and annual operating costs using WaterSense guidelines. We cross-referenced 10% cross-linked resin performance data against resin manufacturer (Purolite, Dow) technical bulletins. Installation guidance is based on the Plumbing Code (IPC/UPC) requirements and manufacturer installation manuals. We do not accept manufacturer compensation for reviews, and all cost comparisons use publicly available retail pricing.