astroboy
Fishaholic
Once ich is in your tank you will never get rid of it....the spots may go away and your fih may seem healthy but there will still be parasites living in the gravel..the filter....wherever they can attach....it is when the fish are stressed or the water conditions are poor that the parasite shows itself as white spots on the fish.....
Thats a myth. Once you kill ick its gone for good. The only way to get it again is to reintroduce it into your tank (no quarantining, cross contamination). People get ick again after treatment because half the time they don't treat all the way (ex. stop treatment once cysts disappear).
Oh yeah, and at high temps ick will die from the temp alone. But there are so many variables that its better to be safe and add salt as well.