Phoenix Hard Water Guide

Water softener salt for Phoenix-area homes

Salt is the one thing a softener keeps asking for. The type you buy matters less than buying the right kind for your softener and keeping the tank from crusting over.

How much softener salt a year, by city and household

40 lb bags a year for each household size at each city's published hardness.

City or area1 person2 people3 people4 people5 people6 people
Phoenix13.8 grains per gallon3about 9 lb a month6about 19 lb a month9about 28 lb a month12about 38 lb a month15about 48 lb a month18about 58 lb a month
Scottsdale, south of Indian School Rd14 grains per gallon3about 10 lb a month6about 19 lb a month9about 29 lb a month12about 38 lb a month15about 48 lb a month18about 58 lb a month
Scottsdale, Indian School to Chaparral Rd15 grains per gallon3about 10 lb a month7about 21 lb a month10about 31 lb a month13about 42 lb a month16about 52 lb a month19about 63 lb a month
Scottsdale, north of Chaparral Rd15 grains per gallon3about 10 lb a month7about 21 lb a month10about 31 lb a month13about 42 lb a month16about 52 lb a month19about 63 lb a month
Mesa, City Zone12 grains per gallon3about 8 lb a month5about 17 lb a month8about 25 lb a month10about 33 lb a month13about 42 lb a month15about 50 lb a month
Mesa, Eastern and Southern Zones16 grains per gallon4about 11 lb a month7about 23 lb a month10about 33 lb a month14about 44 lb a month17about 55 lb a month20about 67 lb a month
Chandler16.5 grains per gallon4about 12 lb a month7about 23 lb a month11about 34 lb a month14about 46 lb a month17about 57 lb a month21about 68 lb a month
Peoria12.4 grains per gallon3about 8 lb a month6about 18 lb a month8about 26 lb a month11about 34 lb a month13about 43 lb a month16about 52 lb a month
Gilbert10.8 grains per gallon3about 8 lb a month5about 15 lb a month7about 23 lb a month9about 30 lb a month12about 38 lb a month14about 45 lb a month
Glendale13.8 grains per gallon3about 9 lb a month6about 19 lb a month9about 28 lb a month12about 38 lb a month15about 48 lb a month18about 58 lb a month
Tempe12.3 grains per gallon3about 8 lb a month5about 17 lb a month8about 26 lb a month11about 34 lb a month13about 43 lb a month16about 51 lb a month
Surprise, Mountain Vista3.9 grains per gallon1about 3 lb a month2about 5 lb a month3about 8 lb a month4about 11 lb a month4about 13 lb a month5about 16 lb a month
Surprise, Desert Oasis6.2 grains per gallon2about 4 lb a month3about 8 lb a month4about 13 lb a month6about 18 lb a month7about 22 lb a month8about 26 lb a month
Surprise, Surprise Foothills5.3 grains per gallon1about 3 lb a month3about 8 lb a month4about 11 lb a month5about 15 lb a month6about 18 lb a month7about 22 lb a month
Surprise, Circle City8.2 grains per gallon2about 6 lb a month4about 12 lb a month5about 17 lb a month7about 23 lb a month9about 28 lb a month11about 34 lb a month
Queen Creek11.5 grains per gallon3about 8 lb a month5about 16 lb a month8about 24 lb a month10about 32 lb a month12about 40 lb a month15about 48 lb a month
Fountain Hills16 grains per gallon4about 11 lb a month7about 23 lb a month10about 33 lb a month14about 44 lb a month17about 55 lb a month20about 67 lb a month

40 lb bags of softener salt a year for a correctly sized softener, at 3,300 grains removed per pound of salt.

The main kinds of softener salt

Kind What it is Good to know
Evaporated salt pellets Very pure salt pressed into pellets The cleanest option; least sludge in the tank
Solar salt crystals Sea water evaporated in the sun Common and widely sold; slightly more residue
Rock salt Mined salt, least refined Leaves more insoluble grit; check your softener’s manual before using it
Potassium chloride A salt-free-of-sodium alternative Costs more and you use more of it; adds no sodium

Brands such as Morton and Diamond Crystal make several of these kinds. What matters is the kind, written on the bag, not the brand.

Pellets or crystals?

Pellets dissolve evenly and suit most brine tanks. Crystals suit some older or two-tank systems that call for them. If your manual names one, use that. If it doesn’t, pellets are the easy default.

Salt bridges and salt mush

A salt bridge is a hard crust that forms above the water in the brine tank. The salt below it gets used up, the crust doesn’t touch the water, and the softener stops making brine. Push down gently with a broom handle; if it gives way into a hollow, break it up.

Salt mush is a layer of sludge at the bottom of the tank, usually from fine or impure salt. It can block the brine pickup. Scoop it out, rinse the tank, and switch to a purer salt.

Topping up

Keep the salt level above the water line and the tank at least a third full. Pouring a whole bag in at once is fine. Note the date you add salt for a couple of months; it’s the easiest way to see whether your softener’s salt use matches the table above.

Potassium instead of sodium

If you’d rather not add sodium to your water, potassium chloride works in most softeners. Expect to use more of it than salt and to pay more per bag. You may need to raise the salt dose setting; the manual explains how.

Common questions

What is the best salt for a water softener?
High-purity evaporated pellets or solar salt crystals made for softeners. They leave the least residue in the brine tank. Check your softener's manual: a few models ask for one type.
How long does a 40 lb bag of salt last in a water softener?
For a Phoenix family of four, about a month. Smaller or lighter-use households can go six weeks or more; in harder water or with more people, a bag goes faster. The table above shows bags a year.
Can I mix different brands or types of softener salt?
Mixing brands of the same type is fine. Mixing pellets and crystals can encourage bridging, so let the tank run low before you switch.