The poly water tanks in our boat, get a redish color staining and sediment in
them. We use well water from the marina, and it has a lot of iron in it. In the
marina showers that get the staining we use oxalic acid in hot water, sprayed
on the shower enclosures, and it cleans it off almost instantlly. It doesn't
work very good with cold water.

I'm looking for something to put in the tanks to clean them, and more
importantlly, the lines. We scrub the tanks on a regular basis, but this
doesn't do much for the lines.

Any ideas? Thanks