Ever tried "no sick fish"?? They have a treatment for ich that worked really well for our tank. It is safe on inverts and corals, you just add it to your main system. Make sure that you remove all of your filtration though. Not sure if they sell it in Calgary but Hidden Reef carries it or did carry it a little while ago. Check out the website:
www.nosickfish.com
It is a little pricey but I would definately recommend it. It's 1 drop per 25 gallons everyday for 1 week.