A softener depends on its salt. The grade you choose affects how clean the brine tank stays, how often you need to clean it, and how much residue collects at the bottom. Tap water across much of the St. Louis area runs hard, so softener use is common in local homes, and the salt matters as much as the unit itself. This guide covers the main salt types, how to read a label, and what to check before you buy.
The main salt types
Most bagged softener salt falls into a few families. The differences come from how the salt was made and what is left in it after processing.
- Evaporated salt is made by dissolving mined salt and boiling off the water. The result is high in purity with few insoluble leftovers, which makes it the cleanest option for the brine tank.
- Solar salt is made by letting brine evaporate in open ponds under the sun. It is often purer than rock salt but can carry more trace material than evaporated salt, so it may leave a light sludge layer over time.
- Rock salt is mined from underground deposits and crushed. It is often the lowest-priced option in local stores, but it usually contains more insoluble material, which can build up in the tank and call for more frequent cleaning.
- Potassium chloride is a salt substitute that some homeowners use in place of sodium-based salt. Check whether your softener manual approves it, since not every unit is set up for it, and expect that it may cost more to run. This guide makes no health claim about either option. If sodium in your household diet is a concern, ask your own clinician.
Pellets, crystals, and blocks
Salt also comes in different forms. Pellets are the most common choice for home units because they dissolve evenly and suit most brine tanks. Crystals dissolve quickly, which some owners like, but they can clump if they absorb moisture. Block salt is compressed and works well in units designed for it, though it is not a fit for every tank. Stay with the form your softener manual lists.
Reading the bag
- Find the stated purity or grade. Higher purity usually means fewer insolubles collecting in the tank.
- Look for a third-party certification seal, which shows the product was tested against a published standard. Confirm the standard named on the bag matches the seal.
- Confirm the form on the bag, pellet, crystal, or block, matches what your unit accepts.
- Inspect the bag for tears, damp spots, or clumping before you carry it home.
Matching salt to a St. Louis basement
Many St. Louis homes keep the softener in a basement, utility room, or garage. Humid summers and cool, damp floors can make bagged salt clump or harden in storage. Set bags on a shelf rather than directly on concrete, close each bag tightly after refilling, and keep spare bags somewhere dry. Winter heating can dry the air, so check stored bags during the colder months too. If your tank tends to form a hard bridge over the water, a purer salt and a regular tank inspection usually help more than changing brands.
Simple checks before you buy
- Open the softener manual and note which salt types and forms it approves.
- Look at the last brine tank cleaning. A heavy sludge layer points toward a purer salt.
- Request a copy of your water report or use a home test kit to confirm how hard your water runs.
- Buy only as much as you can store dry, and use older bags first so stock does not sit for long.
Pick a grade your unit is built for, keep it dry, and inspect the brine tank on a regular schedule. For many St. Louis homes, that routine does more good than the salt label alone.