I used this stuff called Cupermine (MAKE SURE TO USE THIS IN A QT TANK) as this is a cooper base product, I had a MAJOR ich issues, and this is what I did and it worked and saved ALL my fish but one as I didn't catch the problem in time.

Raised my tank temp slowly to 84 degrees.
Slowly dropped my salinity level to 1.019-1.020
put an airstone in my tank, a powerhead and had my aqua clear run (WITH NOTHNG IN IT>) all just for water circulation.
I than soaked my nori, pellets, and frozin mysis shrimp in garlic for 5-10mins (EVERYDAY EVERY FEEDING) I feed 2x a day.
THEN I treated the tank with cupermine ( don't fallow the directions on the bottle is what I was told by Denis at Golds) treat everyday the full dose.
SO I did 3days full dose everyday, same hours appart. THEN on the 3third day before I did another dose I did a 75% waterchange. Then I treated for 2 more days. I then did another waterchange only about 30% this time. Put TONS of carbon in my aqua clear 500. slowly raised my salinity back up to 1.025-1.026 and lowered my temp back down gradually to 80 degrees.
This took care of my ich it was gone and I only lost 1 fish out of 8 in the whole mess I had going on.

This may not be what others would suggest but it is what finally worked in the end for me I am sure many of the great ppl on here will give you great advice as I see some already have, all I can say with my experience is when you notice something wrong or not so normal get on it right away never wait cause usually if you wait its to late and you could potentially lose all or most of your fish. Good luck.