Customer made a bad mistake.....

[CarlD]

Neither is a good idea--it will probably damage the plaster.

Better off trying ascorbic acid--search for it here on Pool Forum

[Jasheon]

That method looks like a product I use called Super Pool Stain Treat. I know it gets rid of metal stains easily but I don't think I have ever tried it on heavy rust stains. I will try the ascorbic acid.

http://www.h2opoolproducts.com/produ...oducts_id=1247

[pilot-werx]

That super stain stuff is no good. Trust me, I have tried it. Your best best bet is pure ascorbic or oxalic acid.

[mbar]

I would try a magic eraser (Mr. Clean), or use some low grade sandpaper. Ascorbic acid does not do a good job on rust stains.

[Jasheon]

Blah, that's what I kind of figured mbar. Super pool stain treat doesn't get rust stains out, so I didn't think this would either.

I will try those things.