If its brown must be iron?
Visiting several local government workshops across the United Arab Emirates it was interesting to so many pumps abandoned because of the (their words) iron oxide iron related bacteria problems.
One look and I could tell this was a calcium problem with some iron staining. With products like EZ ECO and MultiKleen these pumps can all be cleaned, tested, and most put back into production. Just because its brown doesn’t mean it’s an iron oxide issue!