If you have the time and tanks, you can cure ich using their life cycle to your advantage.
In college, we had two 10-gallon aquariums set up with a heater and a small sponge filter in each. One tank had 5 ich infected mollies. The other was empty of fish.
Every day for 3 weeks we would move the fish to the other tank and clean the now-vacated tank (draining it completely and letting it dry overnight). Worked everytime!