Removing "rust" stains

[pierrefromcanada]

My inground pool is about 15 years old with it's original vinyl liner. Recently, I have been noticing what appears to be rust stains, about the size of a dime, in the shallow part of the pool. Vigourous brushing with my vacuum brush fails to remove the spots. I would like some advice before attempting a cleaner which could be potentially damaging to the vinyl.
BTW. Any clue on the origin of these rust spots ????

Thank you for sharing your advice.

 

[JohnT]

Be on the lookout from screws or nails that have fallen in.

They can be removed by placing a vitamin C tablet on top of them and letting it sit for a day or two.

 

[pierrefromcanada]

Thanks a lot for the vitamin tip John !

For your info, these stains are not associated with a rusty nail or some metal object fallen in the pool.
Their origin is a complete mystery !!! the vinyl at the bottom of the pool rests on a cement base. Only the sides (first 4 feet) are galvanised metal. Never picked up a metal object from the pool floor.

Very kind of you to take the time to answer.

Pierre