How'd you know I'd wander in here jsoong
I've had 2 bouts of ich; one with my clown loaches after having them for 2 months (stress induced) and one with some new cardinals in QT. Temps above 86F are fatal for ich, as are salt levels above 2-3 ppm
I treated the loaches with high temps and salt; I treated the cardinals with high temps alone. However, all the fish in the tank were able to handle the salt and/or the temps.
For the loach treatment I raised the temps to 88F over 2 days, and raised salt levels to 3 ppm
over 3. After 5 days there were no ich parasites visible on the loaches (the angelfish and pleco never showed signs). I kept the temps and salt at those levels for a full 2 weeks to be sure I eradicated the ich.
For the cardinals I also had otos and a bamboo shrimp in the QT tank, so I couldn't use meds or salt. Over 2 days I upped the temps to 88F again, and after 4 days there were no more parasites visible on the fish. Again, 2 weeks at those temps to be sure the ich was gone.
As of today, all my fish are fat n healthy, and ich has not raised its head again.
I prefer salt and high temps as they do not muck up the nitrifying bacterial colonies the way the meds do and are just effective. One needs to be sure all the fish which will be in the tank can handle the salt levels or the temps tho to consider using these methods. I know salt isn't recommended for corys; however all your fish may be ok with high temps; you'll need to do a little research to be sure.
If one decides to go the medication route, Quick Cure as jsoong mentions, or RidIch Plus (+) seem to be the most effective; RidIch Plus also seems to be safer for scaleless fish.