Softener causes iron staining even though hardness is removed

Safety: Chemical cleaners should be used according to label directions and with adequate ventilation.

• Test iron levels: Use an iron test kit to determine dissolved iron concentration. If iron is high, a dedicated iron filter may be needed in addition to the softener.
• Use resin cleaner: Add a US Water Systems-approved resin cleaner to the brine well and run a manual regeneration to remove iron deposits from the resin.
• Adjust settings: Increase hardness setting to account for iron (typically add 3–5 gpg per ppm of iron, per manufacturer guidance).
• Consider pre-filtration: If iron is excessive, install an iron filter (e.g., US Water Systems Matrixx iron filter) ahead of the softener.