Empty and rinse the tank first

Start by turning off your water softener and closing the inlet valve. Open the brine tank (the smaller tank that holds salt) and use a wet/dry vacuum or a submersible pump to remove all standing water and brine solution. If you do not have a pump, bail the water out with a bucket — this takes longer but works just as well.

Once the tank is empty, rinse the interior walls with a garden hose on low pressure. Spray from top to bottom, working around the entire tank. Pay attention to corners and the bottom, where sediment and salt residue collect. Do not use a pressure washer; the force can damage the tank's interior coating.

If the tank has a removable basket or grid at the bottom (most do), lift it out carefully and set it aside. You will clean this separately.

Key Takeaways

  • Turn off the softener and close the inlet valve before opening the brine tank to prevent water damage and may support your safety.
  • Remove standing water with a pump or bucket, then rinse the tank walls with a garden hose at low pressure to clear sediment and salt buildup.
  • Soak the tank with a cleaning solution made from water and household bleach or vinegar if you see mold, algae, or heavy mineral deposits.
  • Clean the basket or grid at the bottom of the tank separately, and inspect the brine line and float valve for clogs before reassembling.

Scrub stubborn deposits and mold

If you see white, brown, or black buildup on the tank walls, or if there is a musty smell, the tank needs more than rinsing. Mix a cleaning solution of one part household bleach to ten parts water, or use equal parts white vinegar and water. Pour the solution into the tank until it covers the bottom by about 6 inches.

Let the solution sit for 15 to 30 minutes. Use a soft-bristled brush or a long-handled mop to scrub the walls, paying special attention to corners and the seams where the tank sides meet the bottom. Scrub the basket or grid with the same solution and brush.

After scrubbing, drain the cleaning solution completely. Rinse the tank and all parts with fresh water at least three times to remove all traces of bleach or vinegar. Any leftover cleaning solution will affect your water quality and can damage the resin bed in your softener.

Clean the brine line and float valve

The brine line is the tube that carries salt solution from the tank into the softener. Over time, salt crystals and sediment can clog this line. Locate where the brine line connects to the tank — it usually has a small clip or nut holding it in place.

Disconnect the brine line by loosening the nut or releasing the clip. Hold the line over a bucket and pour warm water through it from the tank end. If water does not flow freely, the line is clogged. Use a straightened wire coat hanger or a plumbing snake to push through the blockage gently. Do not force it; you can crack the line.

While the line is disconnected, check the float valve — a small plastic or metal ball that sits inside the tank and controls water level. If it is stuck or covered in salt crust, soak it in the vinegar-and-water solution for 10 minutes, then rinse and work it up and down by hand until it moves freely. Reconnect the brine line when you are done.

Inspect the basket and grid assembly

The basket or grid at the bottom of the tank prevents salt from entering the brine line. If it is cracked or warped, salt will bypass it and damage your softener's resin bed. Hold the basket up to a light and look for cracks or splits. If you find damage, the basket must be replaced — it cannot be repaired.

If the basket is intact, soak it in your cleaning solution for 15 minutes, then scrub it with a soft brush and rinse thoroughly. Check that all the small holes or slots are clear. Use a toothpick or thin wire to clear any holes that are blocked by salt crystals.

Reinstall the basket or grid carefully, making sure it sits flat on the bottom of the tank and is fully seated. A basket that is not seated properly will shift during the softening cycle and allow salt to escape into the resin bed.

Refill and test the system

Once all parts are clean and reassembled, close the brine tank and refill it with salt. Use the same type of salt your softener requires — either pellets, crystals, or blocks, depending on your model. Check your owner's manual if you are unsure.

Turn the water inlet valve back on and run a manual regeneration cycle. This flushes the system and ensures everything is working correctly. You should hear the softener draw brine from the tank and then rinse. If the brine line does not draw brine, the line may still be clogged or the float valve may not be seated properly — disconnect and check again.

After the regeneration cycle completes, run water at a tap for 2 to 3 minutes. The water may be slightly cloudy at first, but it should clear. If the water remains cloudy or has a chemical smell, run another regeneration cycle to flush out any remaining cleaning solution.

How often to clean your water softener tank

Most water softener tanks do not need cleaning more than once every two to three years if you use the correct salt type and maintain proper water levels. However, if you live in an area with high iron content in your water, or if you see visible buildup or smell mold, clean the tank sooner.

Check the salt level in your brine tank monthly. If the salt level drops below one-quarter full, add more. Low salt levels can cause the tank to dry out, which leads to salt bridging — a hard crust that forms on top and prevents the salt below from dissolving. Bridging is one of the most common reasons tanks need emergency cleaning.

Keep the area around your water softener dry and well-ventilated. Moisture and poor air circulation encourage mold and algae growth inside the tank, even when the tank is sealed. If you notice a musty smell coming from the softener, increase ventilation and clean the tank promptly.

Frequently Asked Questions

Can I use a pressure washer to clean the inside of the tank?

No. Pressure washers can damage the interior coating of the tank and create small cracks where bacteria can grow. Use a garden hose on low pressure or a soft-bristled brush instead. The slower method is safer and just as effective.

What should I do if the brine line is cracked or leaking?

A cracked brine line must be replaced. You can buy replacement lines at hardware stores or online — they are inexpensive and come with new fittings. Turn off the softener, disconnect the old line, and connect the new one using the same fittings. If you are not comfortable doing this, a water softener technician can replace it in under an hour.

Is it safe to use bleach in the tank if I have a septic system?

Bleach in small amounts (the diluted solution recommended here) is generally safe for septic systems, but vinegar is the safer choice if you want to avoid any risk. Vinegar is just as effective at removing mineral deposits and mold, and it breaks down naturally without affecting your septic bacteria.

Why does my tank smell like rotten eggs?

A sulfur or rotten-egg smell usually means bacteria or algae is growing in the tank. This happens when the tank is exposed to light or when salt sits too long without being used. Clean the tank with a bleach solution, keep it in a dark location, and use your salt more regularly. If the smell returns quickly, your water may have high sulfur content — ask a water testing service to check.

Do I need to turn off the water to my whole house to clean the tank?

No. You only need to close the inlet valve on the softener itself. This stops water from entering the softener but does not affect water to the rest of your house. If your softener does not have an inlet valve, you can turn off the main water supply, but it is not necessary for tank cleaning alone.