How much salt should I put in my water softener tank?

Determining how much salt to put in your water softener tank is an important part of maintaining your water softening system. The amount of salt needed depends on several factors, including the size of your tank, the hardness of your water, and your water usage.

What is a water softener?

A water softener is a device that removes minerals like calcium and magnesium from hard water. These minerals are what causes scale buildup on fixtures and appliances and leaves residue on surfaces. Water softeners work through a process called ion exchange. The hard water passes through a tank filled with small resin beads, which are covered with sodium ions. The resin beads attract and latch onto the calcium and magnesium ions, removing them from the water. Sodium ions are released from the beads to take their place. This creates softened water.

Why do you need to add salt?

The resin beads can only hold onto the mineral ions for so long before they become saturated. At this point, the beads need to be recharged with more sodium ions. This recharging process is called regeneration. For regeneration to occur, a concentrated salt solution needs to come into contact with the resin beads. The brine solution flushes the beads and replaces the calcium and magnesium ions with sodium ions again. Once regeneration is complete, the beads can continue removing hardness minerals from the water.

How much salt depends on the capacity of your softener

The amount of salt needed for regeneration depends on the capacity of your water softener unit. Softeners are rated by grain capacity, which refers to the system’s ability to remove hardness minerals before becoming saturated. Common residential softener sizes include:

  • 30,000 grains
  • 45,000 grains
  • 60,000 grains

The higher the grain capacity, the more hardness minerals the softener can hold before needing to recharge. With a higher capacity, you may not need to add salt as frequently.

Water hardness impacts salt requirements

The hardness of your water is another key factor in salt usage for your softener. Hardness refers to the concentration of calcium and magnesium minerals and is measured in grains per gallon (gpg) or milligrams per liter (mg/L). Some guidelines for water hardness levels:

  • 0-3 gpg = soft water
  • 3-6 gpg = moderately hard water
  • 6-9 gpg = hard water
  • 9+ gpg = very hard water

If you have very hard water, your softener will need to remove more calcium and magnesium. This means it will use up the sodium charges on the resin faster and may need more frequent regenerations. Adding the proper amount of salt keeps the beads recharged to continually soften the water.

Household water use affects salt needs

The amount of softened water your household uses will affect how quickly the softener needs to regenerate. With high water use, the softening capacity gets used up faster. Some factors that can increase water use include:

  • Large household with multiple residents
  • Frequent laundering
  • Automatic lawn irrigation systems
  • Teenagers who take long showers
  • Pools and hot tubs that need filling

With high water use, you’ll go through the softener’s capacity faster and need to add salt more often. Low water use households may only need to add salt every month or two.

Use the manufacturer’s salt dose recommendations

The best way to know how much salt to use is to follow the recommendations provided by your softener’s manufacturer. Instructions are typically included in the owner’s manual. Manufacturers provide salt dosage charts or formulas based on the softener’s resin capacity and the hardness of your water supply.

As an example, a 48,000 grain softener regenerating on a 10 gpg hard water supply may recommend using 48,000 * 10 / 1000 = 480 pounds of salt. Some key recommendations when adding salt:

  • Always use clean salt pellets made for water softeners. Rock salt and pellets with dirt can cause problems.
  • Add the recommended amount of salt. Underfilling can lead to hard water. Overfilling wastes salt and water during regeneration.
  • Pour the salt pellets slowly to prevent bridging. Allow pellets to settle in tank before resuming filling.
  • Keep the salt lid in place and secure after filling.

Signs it’s time to add more salt

In addition to regular fill ups per the manufacturer, also watch for these signs that the softener salt is running low and needs topping off:

  • Return of hard water symptoms – Scale on fixtures, mineral spots, residue on dishes
  • Salt level below 6 inches – Check tank and refill if salt is low
  • Error code on control panel – May indicate an issue with brine tank and need to add salt
  • Increased salt use – If salt seems to be depleting faster than normal, tops off the tank

How to add salt to the brine tank

Adding salt to your water softener is a simple process. Follow these steps:

  1. Lift the brine tank lid off and set aside
  2. Check the current salt level – Should be around 1/2 full at minimum
  3. Use a plastic scoop or pour spout to add salt pellets
  4. Add slowly to prevent salt bridging
  5. Fill to around 3-6 inches from top
  6. Replace brine tank lid and ensure it’s secure
  7. Initiate a manual regeneration cycle
  8. Repeat fill as needed based on water use

The video below demonstrates the process of checking the salt level and adding more salt pellets to the brine tank:

Types of salt for water softeners

There are a few varieties of salt pellets made specifically for recharging water softener resin beads:

Standard water softener salt

– Simple evaporated crystal salt formed into pellets

– Provides effective hardness ion removal

– Less expensive but requires frequent filling

Enhanced salt pellets

– Evaporated salt with added resin cleaners

– Helps prevent buildup on resin beads

– Pricier but may extend time between fillings

Potassium chloride pellets

– Potassium rather than sodium chloride

– For those on low-sodium diets

– More expensive than salt pellets

Be sure to use only pellets made for water softener use. Rock salt and generated salt with high impurities can damage softener parts.

Salt pellets vs. salt blocks

Salt pellets are loose crystalline salt formed into small cylinders. Salt blocks are compressed solid bricks or tablets of salt. Pellets are recommended for water softeners for the following reasons:

  • Pellets dissolve easily and fully in the brine tank to efficiently recharge resin beads.
  • Loose pellets don’t bridge in the tank which inhibits brine formation.
  • Pellet salts are made specifically for softening with the right purity.
  • Blocks can develop channels and cracks that hinder brine creation.
  • Blocks may contain binding agents that foul softener components.

Stick with high purity salt pellets labeled for water softener use for best results.

Common problems from insufficient softener salt

Failing to keep enough salt pellets in your softener’s brine tank can cause issues including:

Hard water returns

– Resin beads become exhausted without salt for regeneration

– Allows hardness minerals back into the water supply

Scale buildup on fixtures

– Hard water causes scale formation on faucets, showerheads

– Clogs pipes, reduces flow and pressures

Spotting on dishes and surfaces

– Water evaporates and leaves mineral residue

– Creates film and spots on cleaned dishes, sinks and counters

Decreased softener lifespan

– Hard water can slowly damage resin beads over time if not recharged

– May require costly repairs or replacement sooner

Check salt levels regularly and add more pellets as needed to avoid these problems.

FAQs about water softener salt

Does salt-free water softening exist?

There are some devices claimed to soften water without salt, but most work inconsistently at best. A true salt-free water softener that reliably eliminates hardness ions has not been developed yet. Adding salt to recharge beads is still the only proven effective method.

Where should the salt level be in my brine tank?

A good rule of thumb is to keep the salt level between 1/2 and 3/4 full in the brine tank. Lower than 1/2 full risks inadequate brine formation. Overfilling can cause salt bridging.

Is it bad to run out of softener salt completely?

It’s best not to completely run out of salt before refilling. The resin beads need frequent regeneration to prevent exhaustion. However, the occasional refill lapse shouldn’t significantly damage a water softener.

Can I use any kind of salt in my softener?

No, only use evaporated pellet salts designed specifically for water softeners. Other types of salt may contain contaminants that can foul and damage softener components.

What happens if I put too much salt in my softener?

Overfilling with salt can cause “salt bridging” where pellets clump together restricting water flow. This prevents the brine solution from properly forming. Wasted salt and water also occur during regeneration.


Adding the proper amount of sodium chloride salt pellets to your water softener regularly is crucial for keeping the system working optimally. Pay attention to the size of your resin tank, hardness of your water supply and household usage to determine the right recharge schedule and amount of salt. Following your manufacturer’s salt dosage recommendations provides the safest bet for keeping your softener in good operating condition. Maintaining the brine tank’s salt level between 1/2 and 3/4 full and refilling as needed helps ensure a constant supply of softened water.

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