diseased fishie, please help!!

[princesspam]

I have 2 silver dollars and I think one has an infection, it is growing a kind of white fur?, i have read that it may be an infection and that it can be treated with a salt dip or something?, can anyone tell me the exact thing i need to help it please as i feel like i have mistreat it when i ask for help in an aquatic shop.

 

[WILDER]

Do you mean it looks fluffy where is it on the fish sounds like columnaris.
http/www.flippersandfins.net/flexibacter.htm