Water softeners · how-to

How to clean a brine tank, step by step

The brine tank is the salt bin next to your softener. Over the years it collects sludge from salt impurities, broken-down pellets, and sometimes iron or silt. That sludge can clog the brine line and float, and then the softener stops drawing brine and stops softening. Cleaning the tank takes an afternoon and basic tools. Here is when it is worth doing, how to do it without hurting the softener, and when to call a pro.

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When a brine tank needs cleaning

• Sludge or a dark, mushy layer at the bottom when the salt runs low.
• A salt bridge — a hard crust with an empty space below it. See salt bridges and mushing.
• Water level that will not drop after a regeneration, or water climbing toward the lid. See standing water in the brine tank to triage that first.
• Hard water coming back even though the tank looks full of salt. Confirm with a hardness test — see is your softener working?
• You are switching salt types (for example from sodium chloride to potassium chloride) and want a clean start. See sodium vs potassium chloride.
• It has never been cleaned and the softener is several years old.

What you need

• A wet/dry shop vacuum, or a bucket and a small scoop or cup
• A long-handled scrub brush (nothing metal or abrasive enough to scratch the plastic)
• Mild dish soap and a garden hose or buckets of clean water
• Rubber gloves and old towels
• Fresh, high-purity softener salt for the refill
• Optional: a liquid resin cleaner to run through the next regeneration

Step by step

1. Plan ahead. Stop adding salt a week or two before so the tank is nearly empty when you clean. Less salt means less to haul out.
2. Bypass the softener. Turn the bypass valve to bypass, or unplug the control valve, so it will not regenerate while you work. Your house still has water, just unsoftened.
3. Remove the lid and the brine well cover. Note how the brine well (the tall tube inside the tank) and the float assembly sit so you can put them back the same way. If there is a grid plate or salt platform at the bottom, note its position.
4. Get the old salt and water out. Break up any bridge gently with a broom handle — do not stab at the tank wall or the brine well. Scoop out the loose salt, then use a wet/dry vac or a bucket to remove the brine and sludge.
5. Disconnect if needed. On many units you can tip or lift the empty tank after unclipping the brine line from the valve and moving the overflow hose. Only do this if the manual shows how; if the line or fitting looks brittle, leave it connected and clean in place.
6. Scrub and rinse. Wash the inside with warm water and a little mild dish soap using a long-handled brush. Rinse until no soap or sludge remains. If your manual calls for sanitizing, use only the product and dose it specifies, and rinse it out completely.
7. Clean the brine well and float. Rinse mineral crust off the float stem and make sure the float moves freely. Check the small screen at the bottom of the brine pickup (if your model has one) for debris.
8. Reassemble. Put the grid plate, brine well, and float back exactly as they were. Reconnect the brine line and overflow hose and check that the overflow runs to a drain.
9. Add water and salt. Add a few inches of clean water (or the amount your manual lists), then refill with salt — usually to about half full, staying below the top of the brine well.
10. Return to service and regenerate. Put the valve back in service, then start a manual regeneration so fresh brine is drawn through the resin. Many people add a dose of resin cleaner at this point — see water softener resin cleaner.
11. Check the next day. Test hardness at a kitchen tap and look for water on the floor around the tank.

Keeping it clean longer

• Use high-purity salt. Pellets and evaporated crystals leave less insoluble residue than rock salt. Diamond Crystal lists its Bright & Soft pellets at 99.8% purity and formulated to resist bridging and mushing.
• Do not overfill. Keeping salt about half full and topping up more often reduces bridging in humid basements.
• Look inside every time you add salt. Break up a crust early before it turns into a bridge.
• Iron in the water? Sludge can be rusty. A rust-fighting cleaner helps, but heavy iron needs its own treatment. See iron in well water.

When to call a pro

• The tank, brine line, or overflow fitting is cracked or leaking.
• The tank keeps filling with water after you clean it — that usually points to the float, the brine valve, or the control valve.
• The softener will not draw brine at all after cleaning (a plugged injector or a failed seal).
• Hardness is still getting through after a clean tank, fresh salt, and a regeneration.

Related across the site

• Residential well pump basics — iron and sediment from a well often end up as brine tank sludge
• Sump pump check valves — if your softener drains to the sump pit, keep that discharge flowing

Sources

• Diamond Crystal Bright & Soft pellets Amazon listing and manufacturer page — 99.8% purity; formulated to prevent bridging and mushing; NSF/ANSI/CAN 60 certified.
• Pro Products Res Care RK64N Amazon listing — liquid cleaner for any brand of softener, added before a regeneration.
• Softener owner manuals — water level, salt level, and any approved sanitizing method vary by model.

More in this section

• Standing water in the brine tank
• Salt bridges and mushing
• Water softener resin cleaner
• Is your water softener working?
• Water softeners section hub