Potassium chloride for a water softener on Las Vegas water

Why people switch to potassium chloride

The Southern Nevada Water Authority’s page on home treatment systems explains that a softener coats its resin with sodium or potassium, and the water “trades” its calcium and magnesium for whichever one is in the brine tank. Its list of a softener’s downsides starts with “potential health risks from sodium intake” and “harm to houseplants due to elevated salt content”. Potassium chloride answers part of both, because no sodium is traded in.

Pros and cons of potassium chloride in a valley softener

For it	Against it
Adds potassium, not sodium, to softened Las Vegas water	Each pound clears less hardness, so you refill more often
Potassium is a plant nutrient, unlike sodium	Costs more per bag than sodium chloride
Most softeners take it with a settings change	Not for water with iron or manganese (WaterBoss)
Not classed as hazardous on Morton’s safety data sheet	Not suitable to drink for some people with kidney or heart conditions

The Connecticut Department of Public Health makes the main trade-off plain: using potassium chloride instead of salt “will minimize sodium in the treated water”, and potassium has no maximum level in drinking water rules.

How much more potassium chloride do you need?

More than salt, but the sources disagree on how much. Here is what each one says:

• Water Conditioning & Purification magazine (trade source), 2016. Gary Battenberg gives a hardness recovery capacity of about 5,994 grains per pound for salt and about 4,699 for potassium chloride at 66°F, which he calls “approximately 21 percent less capacity”. Turned around, matching salt would take about 27 percent more potassium chloride by weight (our calculation).
• The same magazine, 2001. Jerry Poe puts the theoretical maximum at 6,000 grains per pound for salt and 4,800 for potassium chloride: 25 percent more potassium chloride by weight to remove the same hardness.
• The same magazine, 2005. Mike Keller writes that “theoretically, for every pound of NaCl used, 1.27 lbs of KCl should be used”, but adds that industry testing suggests the real difference “is not as great as the theoretical amount”.
• North Dakota State University Extension, revised 2022. About 10 percent more potassium chloride is used in each recharge.
• University of Minnesota Water Resources Center, current page. Potassium chloride is “15 to 30% less efficient than sodium chloride”, so you add it more often.

Read together, plan on roughly 10 to 30 percent more than the salt figures for your household. Our tables use 25 percent (the 2001 theoretical figure), so they sit at the cautious end. The page on how much salt a water softener uses has both columns, salt and potassium chloride, for one to six people on valley water. If you haven’t sized the softener itself, size it for your household first, because a softener that is too small burns through any regenerant faster.

Change the setting when you switch

WaterBoss’s owner’s manual says that if potassium chloride replaces salt, “increase your hardness setting by 12% (multiply by 1.12)”. On valley water that turns 16 into about 18. Other makers word it differently, so check your own manual, and see our Las Vegas water softener settings for the starting figure for your area.

What it costs

It costs more than sodium chloride. North Dakota State University Extension says plainly that potassium chloride “is more expensive”, and the University of Minnesota’s page puts it at several times the price. Shelf prices change by store and season, and we could not record a dated price for a valley store, so we don’t print one here. Compare the price per pound on the bag, then multiply your yearly salt need by the extra above.

Potassium chloride, plants and a desert yard

Sodium is the part of softened water that hurts soil, so potassium is the gentler choice outdoors, but it is not a free pass.

• Houseplants. New Mexico State University’s Southwest Yard & Garden column (1999) says potassium-based softeners “may cause less problems” for plants than sodium ones, but warns that potassium can also build up in potting soil to damaging levels. Its advice is to flush salts out of pots regularly and repot.
• Landscapes. A 2000 case study in Water Conditioning & Purification magazine followed a Canadian golf community that switched its softening to potassium chloride: soil potassium on the irrigated course rose and the turf recovered. All three authors worked for the potash or salt industry, so read it as an industry account.
• Valley watering. The Southern Nevada Water Authority’s watering tips say to “water deeply and infrequently”, which washes salts away from roots in our compacted desert soil.

The simplest answer is still to water the yard with unsoftened water from a bypassed tap; see is a water softener bad for plants for how to check which taps are softened. For lawns specifically, see does softened water kill grass.

How much potassium does softening add?

The Connecticut Department of Public Health’s fact sheet gives a simple rule: for every 100 ppm of hardness removed, a potassium chloride softener adds about 76 ppm of potassium (a salt softener adds about 46 ppm of sodium instead). Applied to each area’s published hardness:

On valley water that comes to about 208 mg/L. Health Canada’s guidance on potassium from water softeners (reviewed 2026) says adverse effects “are unlikely in healthy individuals”, but recommends that people with kidney disease, heart disease, high blood pressure or diabetes, or on medicines that affect potassium, avoid drinking water softened with potassium chloride. If that might be you, ask your doctor before switching, or keep a reverse osmosis tap for drinking water and an unsoftened cold tap in the kitchen.

Buying and storing it

Potassium chloride for softeners is sold as pellets. Morton’s safety data sheet for its potassium chloride pellets (2014) lists 95 to 99.5 percent potassium chloride and calls the product not hazardous under the U.S. workplace hazard rules. Store it dry and off the garage floor, the same as softener salt bought in Las Vegas, and don’t top a tank of pellets up with salt.

Sources for this page

• Southern Nevada Water Authority · home treatment systems page and landscape watering tips · undated (checked October 2026) · how softeners trade minerals; sodium and houseplant downsides; water deeply and infrequently.
• Las Vegas Valley Water District · water quality summary · 2026 (2025 data) · 16 grains per gallon.
• Connecticut Department of Public Health · fact sheet on hard water and softeners · updated 2023 · 76 ppm potassium and 46 ppm sodium per 100 ppm hardness removed; potassium has no maximum level.
• Water Conditioning & Purification magazine (trade publication) · articles by Gary Battenberg (2016), Mike Keller (2005) and Jerry Poe (2001) on ion exchange · capacity of potassium chloride and salt per pound; 1.27 lb and 25 percent theoretical figures (the 25 percent is used in our tables). Also a 2000 case study on potassium chloride and turf, by authors from the potash and salt industry.
• North Dakota State University Extension · water softening publication · revised 2022 · about 10% more potassium chloride per recharge; costs more.
• University of Minnesota Water Resources Center · residential softening page · current (checked October 2026) · 15 to 30% less efficient; costs more; refill more often.
• WaterBoss · owner’s manual (2010 edition) · 2010 · switch at any time; raise the setting by 12%; not with iron or manganese; don’t mix salts.
• Morton Salt · safety data sheet for potassium chloride pellets · 2014 · composition; not classified as hazardous.
• New Mexico State University · Southwest Yard & Garden column · 1999 · potassium softeners and houseplants.
• Health Canada · guidance on potassium from water softeners · reviewed 2026 · who should avoid potassium-softened drinking water.