Rust Stain on New Plaster

[mbar]

Try taking a couple of vitamin C tablets, crushing them, putting them in a sock and rubbing it on the stain. You can also use ph down in a sock and doing the same thing. Let us know how this works.

[mas985]

Another method I sometimes use if the stain is small is called the stain eraser which looks like a big rubber eraser and you can get at your local pool store. Also, my plaster installer used 220 grit wet/dry sand paper to remove a few stains in my pool last year.