The short answer
Rust remover salt is softener salt with an added ingredient that helps the softener handle iron. Diamond Crystal says it is formulated for water with high iron content and that rust stains are a sign of iron. A softener can handle dissolved, clear iron, but Penn State Extension says it does not remove iron that has already oxidized to red.
Why iron shows up in this region
The USGS Ground Water Atlas, describing the glacial aquifers of this part of the Midwest, says most of the water contains iron above 300 micrograms per liter, which stains laundry and porcelain plumbing fixtures. It is the same geology that makes the water hard. More on Peoria's water.
Diamond Crystal suggests rust stains are a sign that iron is in your water.
What rust-fighting salt does
- Cargill's sell sheet for its Iron Fighter pellets lists citric acid, an iron complexing agent that helps prevent rust discoloration, plus sodium hexametaphosphate to resist mushing and bridging.
- Morton says its Clean and Protect Plus Rust Defense pellets remove 10 times more iron than plain salt, per regeneration cycle, based on its internal lab testing.
- Morton Water Softeners says rust control salt is effective at controlling iron and manganese buildup in the softener's resin bed.
Where a softener stops helping
Penn State Extension says a softener removes colorless, reduced iron, but not red oxidized iron, meaning iron that has already met air or chlorine. The Illinois Department of Public Health says a softener can remove up to 10 mg/L of dissolved iron.
So if water already comes out of the tap orange, salt alone is not the full answer. Rust remover salt is for the iron your softener can catch, and for keeping it from building up in the resin.
One caution from Morton
Morton Water Softeners notes that over time, fumes from rust salt additives can affect a softener's electronics. Its suggestion is to pour one bag of rust salt into the bottom of the tank and cover it with a bag of regular softener salt. Check your softener's manual for anything specific to your model.
Rust remover salt from Simply Salt
Our Solar Crystals with Rust Remover are the lower priced salt on both plans: $16 a month on Individual and $26 on Household. We chose it because Central Illinois water is hard on softeners. If you would rather run pellets, Morton Clean & Protect is the other option. See both salts.
Common questions
It adds an ingredient that helps the softener deal with iron. Cargill lists citric acid as an iron complexing agent that helps prevent rust discoloration, and Morton Water Softeners says rust control salt helps control iron and manganese buildup in the resin bed.
Diamond Crystal says rust stains are a sign of iron and that iron-fighting salt is formulated for water with high iron content. If you have no staining, regular softener salt may be all you need.
No. Penn State Extension says softeners remove dissolved, colorless iron, not oxidized red iron. The Illinois Department of Public Health says a softener can remove up to 10 mg/L of dissolved iron.
It is made for softeners, but Morton Water Softeners notes additive fumes can affect electronics over time and suggests covering a bag of rust salt with a bag of regular salt.
Sources
Every figure on this page comes from the sources below or from Simply Salt's own published plan details.
- USGS Ground Water Atlas of the United States, HA 730-K
- Diamond Crystal, Iron Fighter pellets
- Cargill, Iron Fighter pellets sell sheet
- Morton Salt, Clean and Protect Plus Rust Defense pellets
- Morton Water Softeners, Rust control salt
- Penn State Extension, Water softening
- Illinois Department of Public Health, Common substances in drinking water
