How To Use Iron Out in a Water Softener (Step-by-Step)

🤝 Our content is written by humans, not AI robots. Learn More

When a water softener regenerates, the brine solution struggles to lift iron deposits from the resin. Over time, the iron particles build up, with harmful effects. This 2002 study found that fouling from 0.2- 8.0 mg/L of iron reduced a water softener’s operating capacity by 6%-16%.

There are a few products designed to target rust and eliminate iron buildup in a water softener resin, and Iron Out is perhaps the most popular.

We’ve been testing and reviewing water softeners for over a decade, and in this guide, we’ve explained how to use Iron Out in a water softener to effectively remove iron from your softener’s resin tank.

How to Use Iron Out in a Water Softener

📖 How to Use Iron Out in a Water Softener: Step By Step

To use Iron Out in a water softener, follow these steps:

Using Iron Out for One-Off or First-Time Use

If you’re using Iron Out as a one-off and/or you’ve never used it in your water softener before, you’ll probably need to clear out higher concentrations of rust and iron build-up from the resin bed.

Here’s how to use Iron Out in your water softener for the first time:

  1. Prepare the powder: Dissolve the Iron Out powder in water. For thorough cleaning, add one cup of Iron Out to half a gallon of cold water. You’ll hear the Iron Out fizzing as it dissolves in the water. Mix it with a spoon to break up clumps and help it to dissolve faster.
  2. Pour the solution into the brine tank: Open the lid of your water softener’s brine tank (salt tank) and pour the solution into the brine well. Note: if your softener doesn’t have a brine well, wait for your salt level to get low, then add the Iron Out directly to the brine tank.
  3. Manually regenerate softener: Program the softener to perform a manual regeneration cycle. This will flush the Iron Out through the resin tank and out of the system.

You can now use your water softener as normal. If you detect a taste or odor in your softened water, the instructions on the bottle say you should manually regenerate your water softener AGAIN, then run cold water from your faucet until the taste/odor is gone.

Pouring iron out in water softener

Using Iron Out for Regular Use & Preventative Maintenance

Ideally, you should be using Iron Out regularly in your water softener. Periodic cleaning will prevent an excess of iron from accumulating in the system.

Here’s how to use Iron Out for regular preventative maintenance in your water softener:

  1. Prepare the powder: Add one quarter-cup of Iron Out to half a gallon of cold water. Mix the solution with a spoon to break up clumps and help the powder to dissolve faster.
  2. Pour the solution into the brine tank: Open the salt tank lid and pour the solution into the brine well.
  3. Manually regenerate softener: Program the softener to perform a manual regeneration cycle. This will flush the Iron Out through the resin tank and out of the system.

🎥 Video Demonstration

Here’s a video demonstration of how to add Iron Out to your water softener’s brine tank.

📑 Final Word: When NOT to use Iron Out in a Water Softener

Using Iron Out is an effective method of cleaning iron deposits out of your water softener resin bed.

But if your water supply has a known iron problem, Iron Out might not be the best solution. We recommend using a dedicated iron filter installed ahead of your water softener, which will remove iron before it can enter the resin and salt tank.

So, rather than using a resin bed cleaner like Iron Out to fix the problem of rust build-up, you’ll prevent it from happening in the first place.

Springwell water softener and iron filter well water treatment system

❔ FAQ

What is Iron Out?

Iron Out is a multi-purpose rust stain removal powder that can be used to prevent and remove rust stains in sinks, bathtubs, washing machines, dishwashers, toilets, and other water-using appliances and fixtures. Iron Out has also become popular as a water softener iron stain removal solution, and is a great tool for preventative maintenance in water softener units.

Iron out

How does Iron out work?

Iron Out works by changing the state of iron, causing it to dissolve into water, which breaks up rust stains and allows the iron particles to be washed away down a drain. It contains sodium dithionite, a sulfur-bearing compound, which reduces iron from +3 to +2 valence, rendering it soluble (dissolvable in water). In its soluble form, iron stains are lifted from the resin and flushed out of the system in the softener discharge.

Is Iron Out safe to use in a water softener?

Yes, Iron Out is safe to use in a water softener when used correctly, as advised by the manufacturer. Iron Out should be used during water softener cleaning, when the unit isn’t in use. That means it can be washed out of the softener while the system is in bypass mode, so there’s no contamination risk. Some ingredients in Iron Out may be toxic to humans, so it’s essential to properly flush it from the resin tank.

Does Iron Out work?

Yes, Iron Out does work. It’s specially formulated to alter the charge of iron particles stuck to the softener resin, dissolving them in water, so they can be flushed out of the system. This should reduce iron fouling in the mineral bed and ensure it lasts as long as possible.

How often should I use Iron Out in water softener?

Ideally, use Iron Out or another resin bed cleaner once a year, or every six months if a water test reveals that your water supply has high iron levels.

water testing with tap score
  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

Scroll to Top