Treating Ick

Question
I need your advise, I have a 40 gal.Mostly comunity fish- Platties- Guppies-snails-and Cory cats;I have noticed fish scrathing, and a white spot on a couple Platties;What is the safest way to treat and cure Ick, not harming my Cory Cats? I can remove my bigger snails.I have Formalin,Malachite ( Quick cure)I dont have a way to seprate my fish showing signs and figure my tank needs treatment, whats the best method? that want harm my Cory Cats.What about salt, I use it in my outdoor Goldfish ponds it dosen't seem to bother tadpoles or snails out side
I would aprreciate your advise, my corys need help

Answer
raise the temp to about 86 degrees... slowly one degree an hour... add the aquarium salt per its instruction label... you would need to remove the snails... snails do quite well in a jar with water... and they should be fine there for a week or so... just change the water once or more per week... ICH has a nine day cycle so with the raised temp it shortens that cycle time to three - four days... Ich is also only vulnerable to meds when it is in the free swimming stage... when it is under the fishes skin the fish protect it from medication that is in the water... try the salt... and if you notice the condition of the fish getting worse... let me know... we may have to medicate but maybe not... sometimes ICH is cured with just salt... dave