Water Softener Water Salty? Causes, Normal Sodium and Fixes

Softened water should not taste like brine. When it does, the usual reason is that the softener drew brine during regeneration but did not rinse it all out before returning to service. Clack’s service manual names three causes for “residual regenerant” in the water: water pressure below 25 psi, the wrong injector size, and a restricted drain line. Too much brine from an oversized salt or refill setting, and a regeneration interrupted by a power outage, cause the same taste. Some added sodium is normal, though, and at high hardness a faint taste can be expected.

How much sodium a softener normally adds

A softener swaps the calcium and magnesium in your water for sodium. NDSU Extension puts the added sodium at about 8 mg/L for every grain per gallon (gpg) of hardness removed. One gpg is 17 mg/L of hardness.

Calculated from NDSU’s 8 mg/L sodium per gpg and 17 mg/L per gpg.

To put that against taste: EPA’s 2003 sodium advisory recommends keeping drinking water at 30 to 60 mg/L of sodium, a threshold based on taste for taste-sensitive people. That figure is advice, not an enforceable limit. EPA also notes that home water softeners can push sodium above 300 mg/L. So on hard well water, a softener that is working correctly can add enough sodium for some people to taste it. What is not normal is a sudden, strong salt taste, especially the morning after a regeneration, or a taste that comes and goes with the regeneration schedule.

On health: EPA’s guidance level of 20 mg/L applies to people on a physician-prescribed diet of 500 mg of sodium per day, and EPA says it should not be extended to the whole population. If you are on a sodium-restricted diet, ask your doctor about softened drinking water.

First test: is it the softener?

Put the softener in bypass, run a cold tap for a minute, and taste. Then return it to service and compare.

• Raw water also tastes salty → the salt is in the well water itself, not the softener. Get it tested for sodium and chloride; see water softeners for how treatment choices change.
• Only softened water tastes salty → work through the causes below.
• Salty only after regeneration nights → most likely a rinse or brine problem in the valve.

Causes and fixes

Regeneration was interrupted

A softener regenerates in steps. On the Fleck 5600SXT these are backwash, brine draw with slow rinse, rapid rinse, and brine tank refill. A power cut during brine draw can leave brine sitting in the resin tank. Clack says its control finishes the remaining regeneration time once power is restored. With any valve, if the time-of-day display is flashing (both manuals use it to signal a power failure), run a manual regeneration to rinse the bed properly. On the Fleck 5600SXT, the user guide says to hold the regeneration button for 5 seconds.

Restricted drain line or drain line flow control

Rinsing depends on water flowing freely to drain. Clack lists a restricted drain line as a cause of residual regenerant, and a drain line that is too long or too high as a cause of poor brine draw. Fleck’s manual specifies a drain line of at least 1/2 in, and 3/4 in when backwash exceeds 7 gpm or the line runs over 20 ft. The drain line flow control (DLFC) is a small fitting at the valve’s drain port. Fleck lists a plugged DLFC as a cause of both excess water in the brine tank and failure to draw brine. Check for kinks, a line that climbs too high, and debris in the DLFC button.

Low water pressure or a plugged injector

The injector uses water pressure to pull brine from the tank and then push rinse water through the resin. Clack says pressure must stay at a minimum of 25 psi; Fleck’s minimum for the 5600SXT is 20 psi. A well on a 20/40 pressure switch falls to 20 psi before the pump restarts, which is below Clack’s minimum, and running other taps during regeneration pulls pressure down further. A plugged injector or injector screen appears in both manuals’ lists for poor brine draw. Remove the injector, clean it and its screen, and reinstall. If your well pressure is marginal, see well pump not working and the pressure tank guide.

Too much brine: salt or refill setting too high

On a Fleck valve, the salt dose is set by how long the brine tank refills. The brine line flow control (BLFC) sets the refill rate: Fleck’s parts list gives 0.25 gpm as 0.75 lb of salt per minute, and 0.50 gpm as 1.5 lb per minute. So a 10-minute refill through a 0.25 gpm BLFC makes about 7.5 lb of salt into brine. Double the refill time and you double the salt. Clack lists an improper refill setting as the first cause of using too much regenerant.

More brine than the bed needs makes rinsing harder and wastes salt. Fleck’s fix for a unit using too much salt is to check the salt setting and actual salt use. The salt dose should be set from your hardness and resin volume; the water softener size calculator shows how capacity and salt dose relate.

Excess water in the brine tank

If the brine tank holds far more water than normal, each regeneration makes more brine than intended. Clack lists improper program settings, a plugged injector, damaged seals, a kinked drain line, a plugged backwash flow controller, and a missing refill flow controller. Fleck adds debris in the brine valve or the brine line flow control.

Wrong injector size or valve setup

Clack lists an incorrect injector size as a cause of residual regenerant, and a mismatched valve body and piston type as a cause of poor performance. Both usually trace to installation or a parts swap. If the taste started right after a new install or service visit, ask the installer to confirm the injector and flow controls match the tank size.

Quick reference

Clearing salty water after the fix

Once the cause is corrected, run a manual regeneration so the bed is rinsed under the corrected conditions. Then flush the plumbing by running cold water at several taps until the taste clears. The water heater holds softened water too, so run the hot taps as well. If the taste returns after the next scheduled regeneration, the fault is still there.

When to call a dealer

Pentair’s 5600SXT user guide tells owners to contact technical support if the water tastes salty, along with soft-water and salt-use problems. Call a dealer or installer if the taste persists after you have checked pressure, the drain line and the injector, or if the fix means changing injectors, pistons or seal stacks. For other symptoms, start with the full water softener troubleshooting guide. If you are replacing the unit, see our picks of water softeners for well water.